上午9:32 | | | Alisson Tezzin | | | quant-ph updates on arXiv.org |

Recent research on quantum contextuality has been strongly centered on device-independent frameworks, such as the many graph approaches to contextuality and the celebrated sheaf-theoretical approach. Contextuality is described in these frameworks as a property of data only, making it possible to characterize and quantify the phenomena regardless of the reasons why it occurs. In this paper we look beyond the data and focus on possible explanations for this experimental fact. We show that a classical system generating contextual data can easily be found if the following conditions are satisfied (1) We only have access to a specific collection of “epistemic” measurements (which, all things considered, is basically Bohr’s view on quantum measurements) and (2) There is a limitation on which of these measurements can be jointly performed. The way we see it, this example indicates that contextuality may be a consequence of the type of measurement taken into account, instead of an intrinsic feature of the system upon which these measurements are performed; if this is correct, the widespread idea that quantum contextuality is a non-classical feature can be avoided.

上午9:32 | | | Francois-Igor Pris | | | quant-ph updates on arXiv.org |

We argue that Anton Zeilinger’s “foundational conceptual principle” for quantum mechanics according to which an elementary system carries one bit of information is an idealistic principle, which should be replaced by a realistic principle of contextuality. Specific properties of quantum systems are a consequence of impossibility to speak about them without reference to the tools of their observation/identification and, consequently, context in which these tools are applied.

上午9:32 | | | Clement Mawby, Jonathan Halliwell | | | quant-ph updates on arXiv.org |

Macrorealism (MR) is the world-view that at all moments of time, a system is definitely in one of the observable states available to it, irrespective of past or future measurements. The Leggett-Garg (LG) inequalities were introduced to test MR and assess for the presence of macroscopic quantum coherence. Since such effects could plausibly be found in various types of macroscopic oscillators, we apply the LG approach to the quantum harmonic oscillator (QHO) and more general bound systems, using a single dichotomic variable Q given by the sign of the oscillator position. We present a simple method to calculate the relevant temporal correlators for any bound system for which the energy eigenspectrum is (exactly or numerically) known. We then apply this result to the QHO for a variety of experimentally accessible states, namely energy eigenstates, and superpositions thereof. For the subspace of states spanned by only the ground state and first excited state, we readily find substantial regions of parameter space in which the two and three-time LG inequalities can each be independently violated or satisfied. We find violations persist (although are reduced) when the sign function defining Q is smeared to reflect experimental imprecision. We also find that LG violations diminish at high energies, showing the expected classicalization. With a Q defined as an arbitrary position coarse graining, we find two-time LG violations even in the ground state, a simple example of a feature recently noted by Bose et al. [Phys. Rev. Lett. 120, 210402 (2018)]. We also show that two-time LG violations in a gaussian state are readily found if the dichotomic variable at one of the times is taken to be the parity operator. To demonstrate the versatility of the technique we developed, we perform an LG analysis for the Morse potential, where we find significant violations for the first excited state.

上午9:32 | | | gr-qc updates on arXiv.org |

Authors: Deaglan J. Bartlett, Harry Desmond, Pedro G. Ferreira, Jens Jasche

Lorentz Invariance Violation in Quantum Gravity (QG) models or a non-zero photon mass, $m_\gamma$, would lead to an energy-dependent propagation speed for photons, such that photons of different energies from a distant source would arrive at different times, even if they were emitted simultaneously. By developing source-by-source, Monte Carlo-based forward models for such time delays from Gamma Ray Bursts, and marginalising over empirical noise models describing other contributions to the time delay, we derive constraints on $m_\gamma$ and the QG length scale, $\ell_{\rm QG}$, using spectral lag data from the BATSE satellite. We find $m_\gamma < 4.0 \times 10^{-5} \, h \, {\rm eV}/c^2$ and $\ell_{\rm QG} < 5.3 \times 10^{-18} \, h \, {\rm \, GeV^{-1}}$ at 95% confidence, and demonstrate that these constraints are robust to the choice of noise model. The QG constraint is among the tightest from studies which consider multiple Gamma Ray Bursts and the constraint on $m_\gamma$, although weaker than from using radio data, provides an independent constraint which is less sensitive to the effects of dispersion by electrons.

Comment on “Maximum force and cosmic censorship”. (arXiv:2109.07700v1 [gr-qc])

上午9:32 | | | gr-qc updates on arXiv.org |

Authors: Christoph Schiller

Despite suggestions to the contrary, no counterargument to the principle of maximum force or to the equivalent principle of maximum power has yet been provided.

Can the Hubble tension be resolved by bulk viscosity?. (arXiv:2107.13533v2 [gr-qc] UPDATED)

上午9:32 | | | gr-qc updates on arXiv.org |

Authors: Ben David Normann, Iver Håkon Brevik

We show that the cosmic bulk viscosity estimated in our previous works is sufficient to bridge the $H_0$ value inferred from observations of the early universe with the value inferred from the local (late) universe.

A computational complexity approach to the definition of empirical equivalence.

2021年9月17日 星期五 上午6:44 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Brogioli, Doriano (2019) A computational complexity approach to the definition of empirical equivalence. [Preprint]

Two Quantum Logics of Indeterminacy

2021年9月17日 星期五 上午6:43 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Fletcher, Samuel C. and Taylor, David E. (2021) Two Quantum Logics of Indeterminacy. Synthese. ISSN 1573-0964

Can Redescriptions of Outcomes Salvage the Axioms of Decision Theory?

2021年9月17日 星期五 上午6:41 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Baccelli, Jean and Mongin, Philippe (2021) Can Redescriptions of Outcomes Salvage the Axioms of Decision Theory? Philosophical Studies. ISSN 0031-8116

Maxwell’s Demon in Quantum Mechanics

2021年9月17日 星期五 上午6:40 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Hemmo, Meir and Shenker, Orly R. (2020) Maxwell’s Demon in Quantum Mechanics. Entropy, 22. p. 269. ISSN 1099-4300

Macroscopically Nonlocal Quantum Correlations

2021年9月16日 星期四 下午6:00 | | | Miguel Gallego and Borivoje Dakić | | | PRL: General Physics: Statistical and Quantum Mechanics, Quantum Information, etc. |

Author(s): Miguel Gallego and Borivoje Dakić

It is usually believed that coarse graining of quantum correlations leads to classical correlations in the macroscopic limit. Such a principle, known as macroscopic locality, has been proved for correlations arising from independent and identically distributed (IID) entangled pairs. In this Letter, …

[Phys. Rev. Lett. 127, 120401] Published Thu Sep 16, 2021

Consciousness, Phenomenal Consciousness, and Free Will

2021年9月15日 星期三 下午12:39 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Sytsma, Justin and Snater, Melissa (2021) Consciousness, Phenomenal Consciousness, and Free Will. [Preprint]

We Cannot Allow a Wikipedia Gap!

2021年9月12日 星期日 下午3:38 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Ross, Sage Rogers (2007) We Cannot Allow a Wikipedia Gap! Spontaneous Generations: A Journal for the History and Philosophy of Science, 1 (1). ISSN 1913-0465

]]>上午9:54 | | | Mario A. Quiroz-Juárez, Zachary A. Cochran, José L. Aragón, Yogesh N. Joglekar, Roberto de J. León-Montiel | | | quant-ph updates on arXiv.org |

Parity-Time (PT) symmetric systems have been widely recognized as fundamental building blocks for the development of novel, ultra-sensitive opto-electronic devices. However, arguably one of their major drawbacks is that they rely on non-linear amplification processes that could limit their potential applications, particularly in the quantum realm. In this work, we show both theoretically and experimentally that gain-loss, PT-symmetric systems can be designed by means of linear, time-modulated components. More specifically, by making use of a state-of-the-art, fully reconfigurable electronic platform, we demonstrate that PT-symmetry breaking transitions can be observed by properly modulating the inductance (L) and the capacitance (C) of a single LC circuit. Importantly, the lossless dynamic-variations of the electrical components used in our LC circuits allow us to control the static and periodic (Floquet) regimes of our PT-symmetric system. Our results challenge the conventional wisdom that at least two-oscillator systems are needed for observing PT-symmetric phenomena, and provide a new perspective in the field of synthetic PT symmetry with important implications for sensing, energy transfer and topology.

Violation $\neq$ Quantum. (arXiv:2109.03871v1 [quant-ph])

上午9:54 | | | Xingyu Guo, Chen-Te Ma | | | quant-ph updates on arXiv.org |

The only entanglement quantity is concurrence in a 2-qubit pure state. The maximum violation of Bell’s inequality is monotonically increasing for this quantity. Therefore, people expect that pure state entanglement is relevant to the quantum violation. To understand the relation between violation and entanglement, we extend the study to three qubits. We consider all possible 3-qubit operators with a symmetric permutation. When only turning on one entanglement measure, the numerical result shows a contradiction to the expectation. The maximum violation does not have the same behavior as in 2-qubit pure states. Therefore, we conclude “Violation$\neq$Quantum”. In the end, we propose the generalized $R$-matrix or correlation matrix for the new diagnosis of Quantum Entanglement. We demonstrate the evidence by restoring the monotonically increasing result.

Spooky action at a distance also acts in the past. (arXiv:2109.04151v1 [quant-ph])

上午9:54 | | | Mandip Singh | | | quant-ph updates on arXiv.org |

The term `spooky action at a distance’ was coined by A. Einstein to show inconsistency of quantum mechanics with the principle of locality and reality. However, quantum mechanics is nonlocal and violates Bell’s inequality. A quantum state measurement of a particle of an entangled pair collapses the total quantum state and the quantum state of the distant particle is immediately determined without making any interaction with it. The isolated collapsed quantum state of both particles remains unentangled in the future. An inertial frame of reference moving with a relativistic speed perceives these events differently is space and time and their simultaneity is relative. In this paper, it is shown that the quantum state collapse happens not only in the present but it also happens in the past of the collapse event.

上午9:54 | | | Guillaume Aubrun, Ludovico Lami, Carlos Palazuelos, Martin Plávala | | | quant-ph updates on arXiv.org |

We prove that any two general probabilistic theories (GPTs) are entangleable, in the sense that their composite exhibits either entangled states or entangled measurements, if and only if they are both non-classical, meaning that neither of the state spaces is a simplex. This establishes the universal equivalence of the (local) superposition principle and the existence of global entanglement, valid in a fully theory-independent way. As an application of our techniques, we show that all non-classical GPTs exhibit a strong form of incompatibility of states and measurements, and use this to construct a version of the BB84 protocol that works in any non-classical GPT.

General Relativity’s energy and positivity — a brief history. (arXiv:2109.03936v1 [physics.hist-ph])

上午9:54 | | | physics.hist-ph updates on arXiv.org |

Authors: S.Deser

I give a brief review of the search for a proper definition of energy in General Relativity (GR), a far from trivial quest, which was only completed after four and a half decades. The equally (or perhaps more) difficult task of establishing its positivity — it was to take another fifteen plus years — will then be summarized. Extension to cosmological GR is included. Mention is made of some recent offshoots.

Chaos-protected locality. (arXiv:2109.03825v1 [quant-ph])

上午9:54 | | | gr-qc updates on arXiv.org |

Authors: Shao-Kai Jian, Brian Swingle

Microscopic speed limits that constrain the motion of matter, energy, and information abound in physics, from the “ultimate” speed limit set by light to Lieb-Robinson speed limits in quantum spin systems. In addition to these state-independent speed limits, systems can also be governed by emergent state-dependent speed limits indicating slow dynamics arising, for example, from slow low-energy quasiparticles. Here we describe a different kind of speed limit: a situation where complex information/entanglement spreads rapidly, in a fashion inconsistent with any speed limit, but where simple signals continue to obey an approximate speed limit. If we take the point of view that the motion of simple signals defines the local spacetime geometry of the universe, then the effects we describe show that spacetime locality can be compatible with a high degree of non-local interactions provided these are sufficiently chaotic. With this perspective, we sharpen a puzzle about black holes recently raised by Shor and propose a schematic resolution.

What actually happens when you approach a gravitational singularity?. (arXiv:2109.04061v1 [gr-qc])

上午9:54 | | | gr-qc updates on arXiv.org |

Authors: Susan M. Scott, Ben E. Whale

Roger Penrose’s 2020 Nobel Prize in Physics recognises that his identification of the concepts of “gravitational singularity” and an “incomplete, inextendible, null geodesic” is physically very important. The existence of an incomplete, inextendible, null geodesic doesn’t say much, however, if anything, about curvature divergence, nor is it a helpful definition for performing actual calculations. Physicists have long sought for a coordinate independent method of defining where a singularity is located, given an incomplete, inextendible, null geodesic, that also allows for standard analytic techniques to be implemented. In this essay we present a solution to this issue. It is now possible to give a concrete relationship between an incomplete, inextendible, null geodesic and a gravitational singularity, and to study any possible curvature divergence using standard techniques.

上午9:54 | | | gr-qc updates on arXiv.org |

Authors: Bodo Lampe

The cosmic time dependencies of $G$, $\alpha$, $\hbar$ and of Standard Model parameters like the Higgs vev and elementary particle masses are studied in the framework of a new dark energy interpretation. Due to the associated time variation of rulers, many effects turn out to be invisible. However, a rather large time dependence is claimed to arise in association with dark energy measurements, and smaller ones in connection with the Standard Model.

上午6:00 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Mitsch, Chris (2021) Hilbert-Style Axiomatic Completion: The (Not So) Hidden Contextuality of von Neumann’s “No Hidden Variables” Theorem. [Preprint]

Quantum Theory Cannot Violate a Causal Inequality

2021年9月10日 星期五 下午6:00 | | | Tom Purves and Anthony J. Short | | | PRL: General Physics: Statistical and Quantum Mechanics, Quantum Information, etc. |

Author(s): Tom Purves and Anthony J. Short

Within quantum theory, we can create superpositions of different causal orders of events, and observe interference between them. This raises the question of whether quantum theory can produce results that would be impossible to replicate with any classical causal model, thereby violating a causal in…

[Phys. Rev. Lett. 127, 110402] Published Fri Sep 10, 2021

Bipartite Measurements in Minkowski Space

2021年9月10日 星期五 上午7:17 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

King, Robbie (2021) Bipartite Measurements in Minkowski Space. [Preprint]

2021年9月10日 星期五 上午7:15 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Leifer, Matthew Saul (2016) A. Douglas Stone. Einstein and the Quantum: The Quest of the Valiant Swabian. 332 pp. Princeton University Press, 2013. Spontaneous Generations: A Journal for the History and Philosophy of Science, 8 (1). pp. 105-108. ISSN 1913-0465

Maxwellian Electrodynamics Genesis and Development: Intertheoretic Context

2021年9月10日 星期五 上午1:05 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Nugayev, Rinat Magdievich (2016) Maxwellian Electrodynamics Genesis and Development: Intertheoretic Context. Spontaneous Generations: A Journal for the History and Philosophy of Science, 8 (1). pp. 55-92. ISSN 1913-0465

2021年9月8日 星期三 上午8:00 | | | Nature Physics – Issue – nature.com science feeds |

Nature Physics, Published online: 08 September 2021; doi:10.1038/s41567-021-01362-5

The European Researchers’ Night provides a platform for scientists to engage with the public.

2021年9月8日 星期三 上午8:00 | | | Richard Brierley | | | Nature Physics – Issue – nature.com science feeds |

Nature Physics, Published online: 08 September 2021; doi:10.1038/s41567-021-01353-6

Even more exotic

Interaction-Free Measurement with Electrons

2021年9月7日 星期二 下午6:00 | | | Amy E. Turner, Cameron W. Johnson, Pieter Kruit, and Benjamin J. McMorran | | | PRL: General Physics: Statistical and Quantum Mechanics, Quantum Information, etc. |

Author(s): Amy E. Turner, Cameron W. Johnson, Pieter Kruit, and Benjamin J. McMorran

Here, we experimentally demonstrate interaction-free measurements with electrons using a novel electron Mach-Zehnder interferometer. The flexible two-grating electron interferometer is constructed in a conventional transmission electron microscope and achieves high contrast in discrete output detect…

[Phys. Rev. Lett. 127, 110401] Published Tue Sep 07, 2021

Four-dimensionalism, eternalism, and deprivationist accounts of the evil of death

2021年9月7日 星期二 上午8:00 | | | Latest Results for Synthese |

**Abstract**

Four-dimensionalists think that we persist over time by having different temporal parts at each of the times at which we exist. Eternalists think that all times are equally real. Deprivationists think that death is an evil for the one who dies because it deprives them of something. I argue that four-dimensionalist eternalism, conjoined with a standard deprivationist account of the evil of death, has surprising implications for what we should think about the evil of death. In particular, given these assumptions, we will lack any grounds for thinking that death is an evil for some individuals for whom we would antecedently expect it to be an evil, namely those individuals who cease to exist at death. Alternatively, we will only have some grounds for thinking that death is an evil for certain individuals for whom we might antecedently be more inclined to think death is not an evil, namely those individuals who survive death, in the sense that they continue to exist after death.

A paradox about sets of properties

2021年9月6日 星期一 上午8:00 | | | Latest Results for Synthese |

**Abstract**

A paradox about sets of properties is presented. The paradox, which invokes an impredicatively defined property, is formalized in a free third-order logic with lambda-abstraction, through a classically proof-theoretically valid deduction of a contradiction from a single premise to the effect that every property has a unit set. Something like a model is offered to establish that the premise is, although classically inconsistent, nevertheless consistent, so that the paradox discredits the logic employed. A resolution through the ramified theory of types is considered. Finally, a general scheme that generates a family of analogous paradoxes and a generally applicable resolution are proposed.

]]>上午10:13 | | | David Edward Bruschi, Andreas W. Schell | | | quant-ph updates on arXiv.org |

We use quantum field theory in curved spacetime to show that gravitational redshift induces a unitary transformation on the quantum state of propagating photons. This occurs for realistic photons characterized by a finite bandwidth, while ideal photons with sharp frequencies do not transform unitarily. We find that the transformation is a mode-mixing operation, and we devise a protocol that exploits gravity to induce a Hong-Ou-Mandel-like interference effect on the state of two photons. Testing the results of this work can provide a demonstration of quantum field theory in curved spacetime.

Causal structure in spin-foams. (arXiv:2109.00986v1 [gr-qc])

上午10:13 | | | Eugenio Bianchi, Pierre Martin-Dussaud | | | quant-ph updates on arXiv.org |

The metric field of general relativity is almost fully determined by its causal structure. Yet, in spin-foam models for quantum gravity, the role played by the causal structure is still largely unexplored. The goal of this paper is to clarify how causality is encoded in such models. The quest unveils the physical meaning of the orientation of the two-complex and its role as a dynamical variable. We propose a causal version of the EPRL spin-foam model and discuss the role of the causal structure in the reconstruction of a semiclassical spacetime geometry.

The Future of Quantum Theory: A Way Out of the Impasse. (arXiv:2109.01028v1 [quant-ph])

上午10:13 | | | Ghislain Fourny | | | quant-ph updates on arXiv.org |

In this letter, we point to three widely accepted challenges that the quantum theory, quantum information, and quantum foundations communities are currently facing: indeterminism, the semantics of conditional probabilities, and the spooky action at a distance. We argue that these issues are fundamentally rooted in conflations commonly made between causal dependencies, counterfactual dependencies, and statistical dependencies. We argue that a simple, albeit somewhat uncomfortable shift of viewpoint leads to a way out of the impossibility to extend the theory beyond indeterminism, and towards the possibility that sound extensions of quantum theory, possibly even deterministic yet not super-deterministic, will emerge in the future. The paradigm shift, which we present here, involves a non-trivial relaxation of the commonly accepted mathematical definition of free choice, leading to non-Nashian free choice, more care with the choice of probabilistic notations, and more rigorous use of vocabulary related to causality, counterfactuals, and correlations, which are three concepts of a fundamentally different nature.

上午10:13 | | | V. S. Gomes, P. R. Dieguez, H. M. Vasconcelos | | | quant-ph updates on arXiv.org |

The realism-based nonlocality (RBN) is a recently introduced measure that differs from the well-known Bell’s nonlocality. For bipartite states, the RBN concerns how much an element of reality associated with a given observable is affected upon local measurements on a subsystem. Here, we present an analytical proof for the unitary invariance of the RBN and that it presents a monotonous behavior upon the action of unital and non-unital local quantum noise. We illustrate our results by employing the two-qubits Werner state and thermal quantum correlated states. We show how the RBN is limited by the initial equilibrium temperature and, especially, that it decays asymptotically with it. These results also corroborate the hierarchy relationship between the quantifiers of RBN and global quantum discord, showing that RBN can capture undetectable nonlocal aspects even for non-discordant states. Finally, we argue how our results can be employed to use the RBN as a security tool in quantum communication tasks.

The Autodidactic Universe. (arXiv:2104.03902v2 [hep-th] UPDATED)

上午10:13 | | | Stephon Alexander, William J. Cunningham, Jaron Lanier, Lee Smolin, Stefan Stanojevic, Michael W. Toomey, Dave Wecker | | | quant-ph updates on arXiv.org |

We present an approach to cosmology in which the Universe learns its own physical laws. It does so by exploring a landscape of possible laws, which we express as a certain class of matrix models. We discover maps that put each of these matrix models in correspondence with both a gauge/gravity theory and a mathematical model of a learning machine, such as a deep recurrent, cyclic neural network. This establishes a correspondence between each solution of the physical theory and a run of a neural network. This correspondence is not an equivalence, partly because gauge theories emerge from $N \rightarrow \infty $ limits of the matrix models, whereas the same limits of the neural networks used here are not well-defined. We discuss in detail what it means to say that learning takes place in autodidactic systems, where there is no supervision. We propose that if the neural network model can be said to learn without supervision, the same can be said for the corresponding physical theory. We consider other protocols for autodidactic physical systems, such as optimization of graph variety, subset-replication using self-attention and look-ahead, geometrogenesis guided by reinforcement learning, structural learning using renormalization group techniques, and extensions. These protocols together provide a number of directions in which to explore the origin of physical laws based on putting machine learning architectures in correspondence with physical theories.

Which way does stimulated emission go?. (arXiv:2108.13943v2 [physics.optics] UPDATED)

上午10:13 | | | J. David Wong-Campos, Trey Porto, Adam E. Cohen | | | quant-ph updates on arXiv.org |

Is it possible to form an image using light produced by stimulated emission? Here we study light scatter off an assembly of excited chromophores. Due to the Optical Theorem, stimulated emission is necessarily accompanied by excited state Rayleigh scattering. Both processes can be used to form images, though they have different dependencies on scattering direction, wavelength and chromophore configuration. Our results suggest several new approaches to optical imaging using fluorophore excited states.

上午10:13 | | | physics.hist-ph updates on arXiv.org |

Authors: Marco Di Mauro, Salvatore Esposito, Adele Naddeo

Richard P. Feynman’s work on gravitation, as can be inferred from several published and unpublished sources, is reviewed. Feynman was involved with this subject at least from late 1954 to the late 1960s, giving several pivotal contributions to it. Even though he published only three papers, much more material is available, beginning with the records of his many interventions at the Chapel Hill conference in 1957, which are here analyzed in detail, and show that he had already considerably developed his ideas on gravity. In addition he expressed deep thoughts about fundamental issues in quantum mechanics which were suggested by the problem of quantum gravity, such as superpositions of the wave functions of macroscopic objects and the role of the observer. Feynman also lectured on gravity several times. Besides the famous lectures given at Caltech in 1962-63, he extensively discussed this subject in a series of lectures delivered at the Hughes Aircraft Company in 1966-67, whose focus was on astronomy and astrophysics. All this material allows to reconstruct a detailed picture of Feynman’s ideas on gravity and of their evolution until the late sixties. According to him, gravity, like electromagnetism, has quantum foundations, therefore general relativity has to be regarded as the classical limit of an underlying quantum theory; this quantum theory should be investigated by computing physical processes, as if they were experimentally accessible. The same attitude is shown with respect to gravitational waves, as is evident also from an unpublished letter addressed to Victor F. Weisskopf. In addition, an original approach to gravity, which closely mimics (and probably was inspired by) the derivation of the Maxwell equations given by Feynman in that period, is sketched in the unpublished Hughes lectures.

上午10:13 | | | physics.hist-ph updates on arXiv.org |

Authors: M.A. Natiello, Hernán G Solari

The force exerted by an electromagnetic body on another body in relative motion, and its minimal expression, the force on moving charges or \emph{Lorentz’ force} constitute the link between electromagnetism and mechanics. Expressions for the force were produced first by Maxwell and later by H. A. Lorentz, but their expressions disagree. The construction process was the result, in both cases, of analogies rooted in the idea of the ether. Yet, the expression of the force has remained despite its production context. We present a path to the electromagnetic force that starts from Ludwig Lorenz’ relational electromagnetism. The present mathematical abduction does not rest on analogies. Following this path we show that relational electromagnetism, as pursued by the G\”ottingen school, is consistent with Maxwell’s transformation laws and compatible with the idea that the “speed of light” takes the same value in all (inertial) frames of reference, while it cannot be conceived on the basis of analogies with material motion.

上午10:13 | | | gr-qc updates on arXiv.org |

Authors: Matteo Luca Ruggiero, Sara Mattiello, Matteo Leone

Why is modern physics still today, more than 100 years after its birth, the privilege of an elite of scientists and unknown for the great majority of citizens? The answer is simple, since modern physics is in general not present in the standard physics curricula, except for some general outlines, in the final years of some secondary schools. But, is it possibile to teach modern physics in primary school? Is it effective? And, also, is it engaging for students? These are the simple questions which stimulated our research, based on an intervention performed in the last year of Italian primary school, focused on teaching gravity, according to the Einsteinian approach in the spirit of the Einstein First project, an international collaboration which aims to teach school age children the concepts of modern physics. The outcomes of our research study are in agreement with previous findings obtained in Australian schools, thus they contribute to validate them and show that there is no cultural effect, since the approach works in different education systems. Finally, our results are relevant also in terms of retention and prove that the students involved really understand the key ideas.

Celestial Holography: Lectures on Asymptotic Symmetries. (arXiv:2109.00997v1 [hep-th])

上午10:13 | | | gr-qc updates on arXiv.org |

Authors: P. B. Aneesh, Geoffrey Compère, Leonardo Pipolo de Gioia, Igor Mol, Bianca Swidler

The aim of these Lectures is to provide a brief overview of the subject of asymptotic symmetries of gauge and gravity theories in asymptotically flat spacetimes as background material for celestial holography.

Popper and the Propensity Interpretation of Probability

上午12:32 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Pence, Charles H. (2021) Popper and the Propensity Interpretation of Probability. [Preprint]

A discussion on the origin of quantum probabilities

2021年9月2日 星期四 下午2:32 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Holik, Federico and Plastino, Angelo and Sáenz, Manuel (2013) A discussion on the origin of quantum probabilities. Annals of Physics, 340 (1). pp. 293-310.

On the assumptions underlying KS-like contradictions

2021年9月2日 星期四 下午2:31 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

de Barros, José Acacio and Jorge, Juan Pablo and Holik, Federico (2021) On the assumptions underlying KS-like contradictions. [Preprint]

Indistinguishability right from the start in standard quantum mechanics

2021年9月2日 星期四 下午2:30 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Holik, Federico and Jorge, Juan Pablo and Massri, César (2020) Indistinguishability right from the start in standard quantum mechanics. [Preprint]

Is the life-world reduction sufficient in quantum physics ?

2021年8月31日 星期二 下午4:02 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Bitbol, Michel (2021) Is the life-world reduction sufficient in quantum physics ? Continental Philosophy Review.

A PHENOMENOLOGICAL ONTOLOGY FOR PHYSICS: Merleau-Ponty and QBism

2021年8月31日 星期二 下午4:00 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Bitbol, Michel (2020) A PHENOMENOLOGICAL ONTOLOGY FOR PHYSICS: Merleau-Ponty and QBism.

A computational complexity approach to the definition of empirical equivalence.

2021年8月31日 星期二 下午3:58 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Brogioli, Doriano (2019) A computational complexity approach to the definition of empirical equivalence. [Preprint]

On the pragmatic and epistemic virtues of inference to the best explanation

2021年8月29日 星期日 上午8:00 | | | Latest Results for Synthese |

**Abstract**

In a series of papers over the past twenty years, and in a new book, Igor Douven (sometimes in collaboration with Sylvia Wenmackers) has argued that Bayesians are too quick to reject versions of inference to the best explanation that cannot be accommodated within their framework. In this paper, I survey their worries and attempt to answer them using a series of pragmatic and purely epistemic arguments that I take to show that Bayes’ Rule really is the only rational way to respond to your evidence.

J.R. Hance, S. Hossenfelder, T.N. Palmer

Bell’s theorem is often said to imply that quantum mechanics violates local causality, and that local causality cannot be restored with a hidden-variables theory. This however is only correct if the hidden-variables theory fulfils an assumption called Statistical Independence. Violations of Statistical Independence are commonly interpreted as correlations between the measurement settings and the hidden variables (which determine the measurement outcomes). Such correlations have been discarded as “finetuning” or a “conspiracy”. We here point out that the common interpretation is at best physically ambiguous and at worst incorrect. The problem with the common interpretation is that Statistical Independence might be violated because of a non-trivial measure in state space, a possibility we propose to call “supermeasured”. We use Invariant Set Theory as an example of a supermeasured theory that violates the Statistical Independence assumption in Bell’s theorem without requiring correlations between hidden variables and measurement settings.

This paper draws on a number of Roger Penrose’s ideas – including the non-Hamiltonian phase-space flow of the Hawking Box, Conformal Cyclic Cosmology, non-computability and gravitationally induced quantum state reduction – in order to propose a radically unconventional approach to quantum gravity: Invariant Set Theory (IST). In IST, the fundamental laws of physics describe the geometry of the phase portrait of the universe as a whole: “quantum” process are associated with fine-scale fractal geometry, “gravitational” process with larger-scale heterogeneous geometry. With this, it becomes possible to explain the experimental violation of Bell Inequalities without having to abandon key ingredients of general relativity: determinism and local causality. Ensembles in IST can be described by complex Hilbert states over a finite set Cp of complex numbers, where p is a large finite integer. The quantum mechanics of finite-dimensional Hilbert spaces is emergent as a singular limit when p→∞. A small modification to the field equations of general relativity is proposed to make it consistent with IST.

]]>上午9:55 | | | Jing-Hui Huang, Xue-Ying Duan, Fei-Fan He, Guang-Jun Wang, Xiang-Yun Hu | | | quant-ph updates on arXiv.org |

Weak measurement has enabled fundamental studies in both experiment and theory of quantum measurement. Numerous researches have indicated that weak measurements have a wide range of application and scientific research value. In our work, we used bibliometric methods to evaluate the global scientific output of research on Weak measurement and explore the current status and trends in this field from 2000 to 2020. The R bibliometric package was used for quantitative and qualitative analyses of publication outputs and author contributions. In total, 636 related articles and reviews were included in the final analysis. The main results were as follows: The number of publications has increased substantially with time. Physical Review A was the most active journal. The country and institution contributing the most to this field were The United States and University Rochester respectively. The analysis of the conceptual structure of keywords indicated that weak measurements were involved a variety of metrology, quantum communication, and nonclassical features of quantum mechanics. Our bibliometric analysis shows that weak measurement research continues to be a hot-spot. The focus has evolved to study quantum information and amplify weak signals.

Objective quantum fields, retrocausality and ontology. (arXiv:2108.11524v1 [quant-ph])

上午9:55 | | | Peter D Drummond, Margaret D Reid | | | quant-ph updates on arXiv.org |

We compare different approaches to quantum ontology. In particular, we discuss an interpretation of quantum mechanics that we call objective quantum field theory (OQFT), which involves retrocausal fields. Here, objective implies the existence of fields independent of an observer, but not that the results of conjugate measurements are predetermined: the theory is contextual. The ideas and analyses of Einstein and Bohr through to more recent approaches to objective realism are discussed. We briefly describe measurement induced projections, the guided wave interpretation, many-universes, consistent histories, and modal theories. These earlier interpretations are compared with OQFT. We argue that this approach is compatible both with Bohr’s quantum complementarity, and Einstein’s objective realism.

上午9:55 | | | physics.hist-ph updates on arXiv.org |

Authors: Slobodan Nedic

After some more than four centuries from the formulation and publication (in Astronomia Nova) of the Kepler’s Equation, which relates the eccentric (and, intermediately, the true) anomaly of the planetary trajectories to the uniformly flowing time, in accordance with his Second (“Area”) law, the subsequently — in course of development of Orbital Mechanics — to the 2nd law related and formally derived non-existent (zero-valued) transverse acceleration is questioned. Certain implications to Elliptic Integration, Symplectic Integration, Symplectic Geometry/Topology, as well as the connection between physical and mathematical continua in the context of the multi-level, scale-invariant mechanics/dynamics (with the augmented central and torquing forces) are also briefly hinted to.

Aether, Dark Energy, and String Compactifications. (arXiv:2108.07536v2 [hep-th] UPDATED)

上午9:55 | | | physics.hist-ph updates on arXiv.org |

Authors: Paul K. Townsend

The 19th century Aether died with Special Relativity but was resurrected by General Relativity in the form of dark energy; a tensile material with tension equal to its energy density. Such a material is provided by the D-branes of string-theory; these can support the fields of supersymmetric particle-physics, although their energy density is cancelled by orientifold singularities upon compactification. Dark energy can still arise from supersymmetry-breaking anti-D-branes but it is probably time-dependent. Recent results on time-dependent compactifications to an FLRW universe with late-time accelerated expansion are reviewed.

Machine learning accelerates quantum mechanics predictions of molecular crystals

上午9:54 | | | ScienceDirect Publication: Physics ReportsScienceDirect RSShttps://www.sciencedirect.com/journal/physics-reportsRSS for NodeTue, 23 Jul 2019 10:02:48 GMTCopyright © 2019 Elsevier B.V. All rights reservedRapid solidification as non-ergodic phenomenonPublication date: 20 July 2019Source: Physics Reports, Volume 818Author(s): P.K. Galenko, D. JouAbstractRapid solidification is a relevant physical phenomenon in material sciences, whose theoretical analysis requires going beyond the limits of local equilibrium statistical physics and thermodynamics and, in particular, taking account of ergodicity breaking and of generalized formulation of thermodynamics. The ergodicity breaking is related to the time symmetry breaking and to the presence of some kinds of fluxes and gradient flows making that an average of microscopic variables along time is different than an average over some chosen statistical ensemble. In fast processes, this is due, for instance, to the fact that the system has no time enough to explore the who |

Publication date: Available online 25 August 2021

**Source:** Physics Reports

Author(s): Yanqiang Han, Imran Ali, Zhilong Wang, Junfei Cai, Sicheng Wu, Jiequn Tang, Lin Zhang, Jiahao Ren, Rui Xiao, Qianqian Lu, Lei Hang, Hongyuan Luo, Jinjin Li

Neutrinos as a probe of curvature. (arXiv:2108.11423v1 [gr-qc])

上午9:54 | | | gr-qc updates on arXiv.org |

Authors: Jafar Khodagholizadeh

Neutrinos, as the anisotropic stress tensor, have a damping effect on the tensor mode perturbation from inflation to the $ \Lambda$ dominated era. First, we study the squared amplitude reduction for the wavelength entering the horizon during radiation and matter-dominated phases in the negatively curved de Sitter spacetime. Then, by comparing with other spatial spacetimes, $ K=0 $ and $K=1$, the highest difference between closed and open cases is seen in the matter-dominated era. Thus, neutrinos can be added as another candidate for determining the nature of space-time.

Weyl-invariant gravity. (arXiv:2108.11788v1 [gr-qc])

上午9:54 | | | gr-qc updates on arXiv.org |

Authors: Meir Shimon

A few implications of a classical Weyl-invariant scalar-tensor (WIST) version of general relativity (GR) are considered. This theory reduces to GR in a particular conformal frame in which the gravitational coupling and active gravitational masses are fixed. As an example, we recast the homogeneous and isotropic Friedmann-Robertson-Walker (FRW) spacetime in the WIST form with static space and monotonically evolving Planck mass. Cosmological redshift is then explained by the time-dependent lapse function. The latter is proportional to the shrinking (in this particular WIST frame) Planck length squared. The conformal Hubble expansion rate is replaced in this description by the logarithmic (conformal) time derivative of the Planck mass.

上午9:54 | | | gr-qc updates on arXiv.org |

Authors: Martin Bojowald

Background independence is often emphasized as an important property of a quantum theory of gravity that takes seriously the geometrical nature of general relativity. In a background-independent formulation, quantum gravity should determine not only the dynamics of space-time but also its geometry, which may have equally important implications for claims of potential physical observations. One of the leading candidates for background-independent quantum gravity is loop quantum gravity. By combining and interpreting several recent results, it is shown here how the canonical nature of this theory makes it possible to perform a complete space-time analysis in various models that have been proposed in this setting. In spite of the background-independent starting point, all these models turn out to be non-geometrical and even inconsistent to varying degrees, unless strong modifications of Riemannian geometry are taken into account. This outcome leads to several implications for potential observations as well as lessons for other background-independent approaches.

Indistinguishability and Negative Probabilities

上午12:16 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

de Barros, J. Acacio and Holik, Federico (2021) Indistinguishability and Negative Probabilities. Entropy. ISSN 1099-4300

上午12:10 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Ritson, Sophie (2021) Constraints and Divergent Assessments of Fertility in Non-empirical Physics in the History of the String Theory Controversy. [Preprint]

The Solution of the Paradox of Achilles and the Tortoise

2021年8月27日 星期五 上午4:03 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Gori, Giuseppe (2019) The Solution of the Paradox of Achilles and the Tortoise. Medium. pp. 1-4.

2021年8月26日 星期四 上午9:01 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Merritt, David (2020) Cosmological realism. [Preprint]

Taming conceptual wanderings: Wilson-Structuralism

2021年8月26日 星期四 上午8:00 | | | Latest Results for Synthese |

**Abstract**

Mark Wilson presents a highly original account of conceptual behavior that challenges many received views about concepts in analytic philosophy. Few attempts have been made to rationally reconstruct Wilson’s framework of patches and facades within a precise semantic framework. I will show how a modified version of the structuralist framework offers a semantic reconstruction of scientific theories capable of modeling Wilson’s ideas about conceptual behavior. Specifically, I will argue that Theory-Elements and a modified version of Theory-Nets explicate respectively Wilson’s patches and facades. I will also demonstrate how several wandering phenomena described by Wilson can be adequately reconstructed within my framework.

The Causal Structure of Reality

2021年8月25日 星期三 上午6:27 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Papineau, David (2021) The Causal Structure of Reality. [Preprint]

Trans-statistical behavior of a multiparticle system in an ontology of properties

2021年8月25日 星期三 上午6:25 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Pasqualini, Matias and Fortin, Sebastian (2021) Trans-statistical behavior of a multiparticle system in an ontology of properties. [Preprint]

The mereology of thermodynamic equilibrium

2021年8月24日 星期二 上午8:00 | | | Latest Results for Synthese |

**Abstract**

The special composition question (SCQ), which asks under which conditions objects compose a further object, establishes a central debate in modern metaphysics. Recent successes of inductive metaphysics, which studies the implications of the natural sciences for metaphysical problems, suggest that insights into the SCQ can be gained by investigating the physics of composite systems. In this work, I show that the minus first law of thermodynamics, which is concerned with the approach to equilibrium, leads to a new approach to the SCQ, the *thermodynamic composition principle* (TCP): Multiple systems in (generalized) thermal contact compose a single system. This principle, which is justified based on a systematic classification of possible mereological models for thermodynamic systems, might form the basis of an inductive argument for universalism. A formal analysis of the TCP is provided on the basis of mereotopology, which is a combination of mereology and topology. Here, “thermal contact” can be analyzed using the mereotopological predicate “self-connectedness”. Self-connectedness has to be defined in terms of mereological sums to ensure that scattered objects cannot be self-connected.

The Multiple-Computations Theorem and the physics of singling out a computation

2021年8月23日 星期一 下午2:23 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Shenker, Orly and Hemmo, Meir (2021) The Multiple-Computations Theorem and the physics of singling out a computation. [Preprint]

The indeterminacy of computation

2021年8月23日 星期一 上午8:00 | | | Latest Results for Synthese |

**Abstract**

Do the dynamics of a physical system determine what function the system computes? Except in special cases, the answer is no: it is often *indeterminate* what function a given physical system computes. Accordingly, care should be taken when the question ‘What does a particular neuronal system do?’ is answered by hypothesising that the system computes a *particular* function. The phenomenon of the indeterminacy of computation has important implications for the development of computational explanations of biological systems. Additionally, the phenomenon lends some support to the idea that a single neuronal structure may perform multiple cognitive functions, each subserved by a different computation. We provide an overarching conceptual framework in order to further the philosophical debate on the nature of computational indeterminacy and computational explanation.

On the Meaning of EPR’s Reality Criterion

2021年8月22日 星期日 上午1:22 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Gomori, Marton and Hofer-Szabó, Gábor (2021) On the Meaning of EPR’s Reality Criterion. [Preprint]

On The Anthropic Argument and The Fine-tuning Argument

2021年8月22日 星期日 上午1:20 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Merriam, Paul (2021) On The Anthropic Argument and The Fine-tuning Argument. UNSPECIFIED.

Fair Infinite Lotteries, Qualitative Probability, and Regularity

2021年8月22日 星期日 上午1:19 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

DiBella, Nicholas (2021) Fair Infinite Lotteries, Qualitative Probability, and Regularity. [Preprint]

]]>2021年8月20日 星期五 下午3:42 | | | Edward J. Gillis | | | quant-ph updates on arXiv.org |

When a measurement is made on a system that is not in an eigenstate of the measured observable, it is often assumed that some conservation law has been violated. Discussions of the effect of measurements on conserved quantities often overlook the possibility of entanglement between the measured system and the preparation apparatus. The preparation of a system in any particular state necessarily involves interaction between the apparatus and the system. Since entanglement is a generic result of interaction, as shown by Gemmer and Mahler[1], and by Durt[2,3] one would expect some nonzero entanglement between apparatus and measured system, even though the amount of such entanglement is extremely small. Because the apparatus has an enormous number of degrees of freedom relative to the measured system, even a very tiny difference between the apparatus states that are correlated with the orthogonal states of the measured system can be sufficient to account for the perceived deviation from strict conservation of the quantity in question. Hence measurements need not violate conservation laws.

2021年8月20日 星期五 下午3:42 | | | Fabrizio Tamburini, Ignazio Licata | | | quant-ph updates on arXiv.org |

We propose a new thought experiment, based on present-day Quantum Information Technologies, to measure quantum gravitational effects through the Bose-Marletto-Vedral (BMV) effect by revealing the gravitational $t^3$ phase term, its expected relationships with low-energy quantum gravity phenomena and test the equivalence principle of general relativity. The technique here proposed promise to reveal gravitational field fluctuations from the analysis of the stochastic noise associated to an ideal output of a measurement process of a quantum system. To improve the sensitivity we propose to cumulate the effects of the gravitational field fluctuations in time on the outputs of a series of independent measurements acted on entangled states of particles, like in the building of a quantum cryptographic key, and extract from the associated time series the effect of the expected gravitational field fluctuations. In fact, an ideal quantum cryptographic key, built with the sharing of maximally entangled states of particles, is represented by a random sequence of uncorrelated symbols mathematically described by a perfect white noise, a stochastic process with zero mean and without correlation between its values taken at different times. Gravitational field perturbations, including quantum gravity fluctuations and gravitational waves, introduce additional phase terms that decohere the entangled pairs used to build the quantum cryptographic key, with the result of coloring the white noise. We find that this setup, built with massive mesoscopic particles, can potentially reveal the $t^3$ gravitational phase term and thus, the BMV effect.

Comment on `Relativistic wave-particle duality for spinors’. (arXiv:2103.04468v2 [gr-qc] UPDATED)

2021年8月20日 星期五 下午3:42 | | | Carl F. Diether, III, Joy Christian (Oxford) | | | quant-ph updates on arXiv.org |

In a recent paper [1], it has been proposed that relativistic wave-particle duality can be embodied in a relation that shows that the four-velocity of a particle is proportional to the Dirac four-current. In this note we bring out some problems with that idea. In particular, we point out that, in line with existing literature on Einstein-Cartan gravity with torsion, the spin-torsion term should represent negative energy. Moreover, if what is proposed in Eq. (20) of [1] is correct, then the spin torsion term would be zero in the rest frame of the fermion. We suggest a possible resolution of that dilemma.

2021年8月20日 星期五 下午3:42 | | | Du Xin-Dong, Long Chao-Yun | | | quant-ph updates on arXiv.org |

We first give a way which satisfies the bidirectional derivation between the generalized uncertainty principle and the corrected entropy of black holes. By this way, the generalized uncertainty principle can be indirectly modified by some correction elements which are carrried by the corrected entropy. Then we put an entropy modified by quantum tunneling into the way, from which we get a new generalized uncertainty principle, and finally find the new one has a broader form and a stronger adaptability to the sign of parameter.

2021年8月20日 星期五 下午3:42 | | | gr-qc updates on arXiv.org |

Authors: Fabrizio Corelli, Taishi Ikeda, Paolo Pani

We perform extensive nonlinear numerical simulations of the spherical collapse of (charged) wavepackets onto a charged black hole within Einstein-Maxwell theory and in Einstein-Maxwell-scalar theory featuring nonminimal couplings and a spontaneous scalarization mechanism. We confirm that black holes in full-fledged Einstein-Maxwell theory cannot be overcharged past extremality and no naked singularities form, in agreement with the cosmic censorship conjecture. We show that naked singularities do not form even in Einstein-Maxwell-scalar theory, although it is possible to form scalarized black holes with charge above the Reissner-Nordstr\”om bound. We argue that charge and mass extraction due to superradiance at fully nonlinear level is crucial to bound the charge-to-mass ratio of the final black hole below extremality. We also discuss some “descalarization” mechanisms for scalarized black holes induced either by superradiance or by absorption of an opposite-charged wavepacket; in all cases the final state after descalarization is a subextremal Reissner-Nordstr\”om black hole.

2021年8月20日 星期五 上午1:53 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Stoica, Ovidiu Cristinel (2021) World Theory. [Preprint]

A Mathematical Perspective on How Qualia Arise from Their Physical Correlates

2021年8月20日 星期五 上午1:49 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Leffler, T.R. (2021) A Mathematical Perspective on How Qualia Arise from Their Physical Correlates. [Preprint]

Generation of optical Schrödinger cat states in intense laser–matter interactions

2021年8月19日 星期四 上午8:00 | | | P. Tzallas | | | Nature Physics – Issue – nature.com science feeds |

Nature Physics, Published online: 19 August 2021; doi:10.1038/s41567-021-01317-w

Schrödinger cat states are observed in intense laser–atom interactions. These are a superposition of the initial state of the laser and the coherent state that results from the interaction between the light and atoms.

Relational physics and the concept of continuity.

2021年8月19日 星期四 上午6:18 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Prokopov, Aleksey (2021) Relational physics and the concept of continuity. [Preprint]

Experimental Detection of the Correlation Rényi Entropy in the Central Spin Model

2021年8月18日 星期三 下午6:00 | | | Mohamad Niknam, Lea F. Santos, and David G. Cory | | | PRL: General Physics: Statistical and Quantum Mechanics, Quantum Information, etc. |

Author(s): Mohamad Niknam, Lea F. Santos, and David G. Cory

We propose and experimentally measure an entropy that quantifies the volume of correlations among qubits. The experiment is carried out on a nearly isolated quantum system composed of a central spin coupled and initially uncorrelated with 15 other spins. Because of the spin-spin interactions, inform…

[Phys. Rev. Lett. 127, 080401] Published Wed Aug 18, 2021

An algebraic approach to physical fields

2021年8月18日 星期三 下午2:59 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Chen, Lu and Fritz, Tobias (2021) An algebraic approach to physical fields. [Preprint]

Problems of empirical solutions to the theory-ladenness of observation

2021年8月18日 星期三 上午8:00 | | | Latest Results for Synthese |

**Abstract**

Recent years have seen enticing empirical approaches to solving the epistemological problem of the theory-ladenness of observation. I group these approaches in two categories according to their method of choice: testing and refereeing. I argue that none deliver what friends of theory-neutrality want them to. Testing does not work because both evidence from cognitive neuroscience and perceptual pluralism independently invalidate the existence of a common observation core. Refereeing does not work because it treats theory-ladenness as a kind of superficial, removable bias. Even if such treatment is plausible, there is likely no method to ascertain that effects of this bias are not present. More importantly, evidence from cognitive neuroscience suggests that a deeper, likely irremovable kind of theory-ladenness lies within the perceptual modules.

What Breathers Fire into the Equations

2021年8月16日 星期一 下午3:44 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Loewer, Barry (2021) What Breathers Fire into the Equations. UNSPECIFIED.

Time’s Arrow Points to Many Worlds

2021年8月16日 星期一 下午3:42 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Gao, Shan (2021) Time’s Arrow Points to Many Worlds. [Preprint]

Indeterministic finite-precision physics and intuitionistic mathematics

2021年8月16日 星期一 上午4:23 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

van der Lugt, Tein (2020) Indeterministic finite-precision physics and intuitionistic mathematics. [Preprint]

]]>上午9:21 | | | Yu Wang | | | quant-ph updates on arXiv.org |

The position and momentum distributions play an important role in the determination of classical and quantum states, which reveals a fundamental gap between classical and quantum world. For finite dimensional quantum system, a particle moving in one spatial dimension is expressed as a pure quantum state and projective measurements onto two special orthonormal bases are regarded as the observations of position and momentum, which are not enough for the uniquely determination of pure qudit states. In this paper, we focus on the determination of all finite dimensional pure quantum states with projective measurements onto two orthonormal bases. Firstly, a new orthonormal basis is constructed for the replacement of discrete analogy of momentum, which can help to filter out finite candidates among all pure qudit states with probability 1. Then, the analogy bases for position and momentum are enough to determine almost all pure qudits when introducing an adaptive POVM.

上午9:21 | | | Ehtibar N. Dzhafarov | | | quant-ph updates on arXiv.org |

Traditional Bell criteria of contextuality/nonlocality can be derived without any falsifiable assumptions, such as context-independent mapping (or local causality), free choice, or no-fine-tuning. This is achieved by deriving Bell criteria for systems with disturbance, based on the generalized definition of contextuality in the Contextuality-by-Default approach, and then specializing these criteria to systems with no disturbance. Context-independent mapping and no-fine-tuning are derived rather than assumed, and free choice follows from context-independent mapping. KEYWORDS: Bell criteria; contextuality; context-independent mapping; free choice; local causality; no-fine-tuning; nonlocality.

上午9:21 | | | Alexey V. Veryaskin, Michael E. Tobar | | | quant-ph updates on arXiv.org |

The era of practical terrestrial applications of gravity gradiometry begun in 1890 when Baron Lorand von E\”otv\”os, a Hungarian nobleman and a talented physicist and engineer, invented his famous torsion balance – the first practical gravity gradients measuring device. It was credited for the major oil discoveries later in Texas (USA). A 100 years later Kasevich and Chu pioneered the use of quantum physics for gravity gradient measurements. Since then cold-atom gravity gradiometers, or matter-wave gravity gradiometers, had been under development at almost every physics department of top-rated universities around the globe. After another 30 years since the Kasevich and Chu publication in 1992, which had led to the first ever quantum gravity gradiometer, the corresponding research and development ceased from being profoundly active a few years back. This article is an attempt to understand and explain what may have happened to the Quantum Invasion into the area of applied physics and precision engineering that traditionally has been occupied by non-quantum technologies developed for about a 130 years of the history of gravity gradiometry.

上午9:21 | | | Ingita Banerjee, Kornikar Sen, Chirag Srivastava, Ujjwal Sen | | | quant-ph updates on arXiv.org |

Quantum coherence quantifies the amount of superposition in a quantum system, and is the reason and resource behind several phenomena and technologies. It depends on the natural basis in which the quantum state of the system is expressed, which in turn hinges on the physical set-up being analyzed and utilized. While quantum coherence has hitherto been conceptualized by employing different categories of complete bases, there do exist interesting physical situations, where the natural basis is an incomplete one, an example being an interferometric set-up with the observer controlling only a certain fraction of all the slits. We introduce a quantification of quantum coherence with respect to an arbitrary incomplete basis for general quantum states, and develop the corresponding resource theory, identifying the free states and operations. Moreover, we obtain a complementarity relation between the so-defined quantum coherence and the which-path information in an interferometric set-up with several slits, of which only a section is in control of the observer or is accessible to her. This therefore provides us with another face of the wave-particle duality in quantum systems, demonstrating that the complementarity is functional in more general set-ups than thus far considered.

On Complex numbers in Quantum Mechanics. (arXiv:2108.05715v1 [physics.gen-ph])

上午9:21 | | | Faical Barzi | | | quant-ph updates on arXiv.org |

We look at the fundamental use of complex numbers in Quantum Mechanics (QM). A review of some of the most popular reasons given in the literature to support the necessity of the complex formalism, We add some insight by invoking others. This short study is aimed at strengthening the delicate pedagogical endeavor of explaining Why Quantum mechanics needs complex numbers

上午9:21 | | | Dong Jin Lee, Dong-han Yeom | | | quant-ph updates on arXiv.org |

In this paper, we critically revisit the Horowitz-Maldacena proposal and its generalization by Lloyd. In the original proposal, as well as in Lloyd’s generalization, Hawking radiation involves a pair of maximally entangled quantum states in which the ingoing partner state and the collapsed matter form either a maximally entangled pair or a Schmidt decomposed random state near the singularity. We point out that the unitary matrix introduced in Lloyd’s fidelity calculation depends on initial matter states; hence, his result on the high average fidelity may not represent an almost unitary evolution. In opposition to Lloyd’s conclusion, when we do not include the state-dependent unitary matrix for the fidelity computation, we analytically and numerically confirm that information will almost certainly be lost because the fidelity will approach zero as the degrees of freedom increase.

上午9:21 | | | physics.hist-ph updates on arXiv.org |

Authors: Tein van der Lugt

In recent publications in physics and mathematics, concerns have been raised about the use of real numbers to describe quantities in physics, and in particular about the usual assumption that physical quantities are infinitely precise. In this thesis, we discuss some motivations for dropping this assumption, which we believe partly arises from the usual point-based approach to the mathematical continuum. We focus on the case of classical mechanics specifically, but the ideas could be extended to other theories as well. We analyse the alternative theory of classical mechanics presented by Gisin and Del Santo, which suggests that physical quantities can equivalently be thought of as being only determined up to finite precision at each point in time, and that doing so naturally leads to indeterminism. Next, we investigate whether we can use intuitionistic mathematics to mathematically express the idea of finite precision of quantities, arriving at the cautious conclusion that, as far as we can see, such attempts are thwarted by conceptual contradictions. Finally, we outline another approach to formalising finite-precision quantities in classical mechanics, which is inspired by the intuitionistic approach to the continuum but uses classical mathematics.

Future Boundaries and the Black Hole Information Paradox. (arXiv:2108.05744v1 [hep-th])

上午9:21 | | | gr-qc updates on arXiv.org |

Authors: Malcolm J. Perry

The black hole information paradox is the incompatibility of quantum mechanics with the semi-classical picture of Hawking radiation. Hawking radiation appears thermal and eventually leads to the complete disappearance of a black hole. However, black holes could be formed from a pure quantum state. The transition from such an initial state to the final state of pure Hawking radiation cannot be described by unitary time evolution. In this paper, we present an analysis in quantum gravity that shows how boundary conditions in the future prevent a loss of quantum mechanical information from the spacetime. In classical physics, the future boundary of the spacetime in the black hole interior is a singularity. Realistic gravitational collapse results in a BKL type of approach to the singularity. But, solving the Wheeler-DeWitt equation reveals that the singularity does not form and can be replaced by specifying a final state density matrix. Such a condition is natural within the context of consistent histories version of quantum mechanics. We provide a self-contained treatment of these issues. How information escapes from the black hole will be treated elsewhere.

Quantum metaphysical indeterminacy and worldly incompleteness

上午4:44 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Torza, Alessandro (2017) Quantum metaphysical indeterminacy and worldly incompleteness. Synthese, 197. pp. 4251-4264. ISSN 1573-0964

上午4:44 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Torza, Alessandro (2021) Quantum metametaphysics. Synthese. ISSN 1573-0964

Relativistic limits on quantum operations

2021年8月12日 星期四 下午3:12 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

van der Lugt, Tein (2021) Relativistic limits on quantum operations. [Preprint]

When statistical evidence is not specific enough

2021年8月12日 星期四 上午8:00 | | | Latest Results for Synthese |

**Abstract**

Many philosophers have pointed out that statistical evidence, or at least some forms of it, lack desirable epistemic or non-epistemic properties, and that this should make us wary of litigations in which the case against the defendant rests in whole or in part on statistical evidence. Others have responded that such broad reservations about statistical evidence are overly restrictive since appellate courts have expressed nuanced views about statistical evidence. In an effort to clarify and reconcile, I put forward an interpretive analysis of why statistical evidence should raise concerns in some cases but not others. I argue that when there is a mismatch between the specificity of the evidence and the expected specificity of the accusation, statistical evidence—as any other kind of evidence—should be considered insufficient to sustain a conviction. I rely on different stylized court cases to illustrate the explanatory power of this analysis.

Converting Contextuality into Nonlocality

2021年8月11日 星期三 下午6:00 | | | Adán Cabello | | | PRL: General Physics: Statistical and Quantum Mechanics, Quantum Information, etc. |

Author(s): Adán Cabello

We introduce a general method which converts, in a unified way, any form of quantum contextuality, including any form of state-dependent contextuality, into a quantum violation of a bipartite Bell inequality. As an example, we apply the method to a quantum violation of the Klyachko-Can-Binicioğlu-Sh…

[Phys. Rev. Lett. 127, 070401] Published Wed Aug 11, 2021

Super-Humeanism and mental causation

2021年8月10日 星期二 下午12:34 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Esfeld, Michael (2021) Super-Humeanism and mental causation. [Preprint]

Situated Observation in Bohmian Mechanics

2021年8月10日 星期二 下午12:32 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Barrett, Jeffrey A. (2021) Situated Observation in Bohmian Mechanics. [Preprint]

2021年8月9日 星期一 上午8:00 | | | David Abergel | | | Nature Physics – Issue – nature.com science feeds |

Nature Physics, Published online: 09 August 2021; doi:10.1038/s41567-021-01330-z

Topological breakdown

Hans Reichenbach, radio philosopher: a preliminary report

2021年8月9日 星期一 上午8:00 | | | Latest Results for Synthese |

**Abstract**

This essay looks at some of the key aspects of Hans Reichenbach’s career as a radio engineer, broadcaster, and producer. It argues that some of the themes of Reichenbach’s logical empiricism can be illuminated by looking at them in relation to his work as a radio engineer during and after World War One. It also argues that attention to the educational activities he undertook in the new broadcast radio medium can help us understand that affinities he saw between logical empiricism and other modernizing projects of Weimar Germany.

Asymmetry cannot solve the circularity/regress problem of property structuralism

2021年8月9日 星期一 上午8:00 | | | Latest Results for Synthese |

**Abstract**

Strong dispositional monism (SDM), the position that all fundamental physical properties consist in dispositional relations to other properties, is naturally construed as property structuralism. J. Lowe’s circularity/regress objection (CRO) constitutes a serious challenge to SDM that questions the possibility of a purely relational determination of all property essences. The supervenience thesis of A. Bird’s graph-theoretic asymmetry reply to CRO can be rigorously proved. Yet the reply fails metaphysically, because it reveals neither a metaphysical determination of identities on a purely relational basis nor a determination specifically of identities in the sense of essences. Asymmetry is thus not by itself sufficient for a solution to CRO. But it cannot even help to answer CRO when a model for the determination of essences is taken as a basis. Nor is asymmetry necessary for a reply, as property structures may well be symmetric. A metaphysics of dispositional properties as grounded in a purely relational structure faces serious obstacles, and the properties would not be fundamental. Since essence and grounding are notions of metaphysical priority, there can be no essentially dispositional metaphysically fundamental properties, and the prospects of a “coherentist” metaphysics of basic properties are dim. A modal retreat that refrains from a post-modal conception of essence and simply claims that fundamental properties play dispositional roles by metaphysical necessity is unsatisfactory.

Everettian Mechanics with Hyperfinitely Many Worlds

2021年8月8日 星期日 上午11:53 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Barrett, Jeffrey A. and Goldbring, Isaac (2021) Everettian Mechanics with Hyperfinitely Many Worlds. [Preprint]

Putting probabilities first. How Hilbert space generates and constrains them

2021年8月8日 星期日 上午11:52 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Janas, Michael and Cuffaro, Michael E. and Janssen, Michel (2019) Putting probabilities first. How Hilbert space generates and constrains them. [Preprint]

]]>上午10:04 | | | Boaz Tamir, Ismael L. Paiva, Zohar Schwartzman-Nowik, Eliahu Cohen | | | quant-ph updates on arXiv.org |

Logical entropy gives a measure, in the sense of measure theory, of the distinctions of a given partition of a set, an idea that can be naturally generalized to classical probability distributions. Here, we analyze how fundamental concepts of this entropy and other related definitions can be applied to the study of quantum systems, leading to the introduction of the quantum logical entropy. Moreover, we prove several properties of this entropy for generic density matrices that may be relevant to various areas of quantum mechanics and quantum information. Furthermore, we extend the notion of quantum logical entropy to post-selected systems.

The Quantum Theory of Time: a Calculus for Q-numbers. (arXiv:2108.02771v1 [quant-ph])

上午10:04 | | | Samuel Kuypers | | | quant-ph updates on arXiv.org |

In quantum theory, physical systems are usually assumed to evolve relative to a c-number time. This c-number time is unphysical and has turned out to be unnecessary for explaining dynamics: in the timeless approach to quantum theory developed by Page & Wootters (1983), subsystems of a stationary universe can instead evolve relative to a ‘clock’, which is a quantum system with a q-number time observable. Page & Wootters formulated their construction in the Schr\”odinger picture and left open the possibility that the c-number time still plays an explanatory role in the Heisenberg picture. I formulate their construction in the Heisenberg picture and demonstrate that the c-number time is completely unnecessary in that picture, too. When the Page-Wootters construction is formulated in the Heisenberg picture, the descriptors of physical systems are functions of the clock’s q-number time, and derivatives with respect to this q-number time can be defined in terms of the clock’s algebra of observables, resulting in a calculus for q-numbers.

上午10:04 | | | Jose Bernabeu, Antonio Di Domenico | | | quant-ph updates on arXiv.org |

Entangled neutral K-mesons allow the study of their correlated dynamics at interference and decoherence times not accessible in any other system. We find novel quantum phenomena associated to a correlation-in-time between the two partners: the past state of the first decayed Kaon, when it was entangled before its decay, is influenced by the result and the time of the future observation of the second decay channel. This surprising “from future to past” effect is fully observable and leads to the unique experimental tag of the KS-state, an unsolved problem since the discovery of CP violation.

Scientific Objectivity and its Limits. (arXiv:2010.01013v2 [quant-ph] UPDATED)

上午10:04 | | | Richard Healey | | | quant-ph updates on arXiv.org |

Measurement outcomes provide data for a physical theory. Unless they are objective they support no objective scientific knowledge. So the outcome of a quantum measurement must be an objective physical fact. But recent arguments purport to show that if quantum theory is universally applicable then there is no such fact. This calls for a reappraisal of the notions of fact and objectivity. If quantum theory is universally applicable the facts about the physical world include a fact about each quantum measurement outcome. These physical facts lack an ideal kind of objectivity but their more modest objectivity is all that science needs.

Trapped electrons and ions as particle detectors. (arXiv:2104.05737v2 [quant-ph] UPDATED)

上午10:04 | | | Daniel Carney, Hartmut Häffner, David C. Moore, Jacob M. Taylor | | | quant-ph updates on arXiv.org |

Electrons and ions trapped with electromagnetic fields have long served as important high-precision metrological instruments, and more recently have also been proposed as a platform for quantum information processing. Here we point out that these systems can also be used as highly sensitive detectors of passing charged particles, due to the combination of their extreme charge-to-mass ratio and low-noise quantum readout and control. In particular, these systems can be used to detect energy depositions many orders of magnitude below typical ionization scales. As illustrations, we suggest some applications in particle physics. We outline a non-destructive time-of-flight measurement capable of sub-eV energy resolution for slowly moving, collimated particles. We also show that current devices can be used to provide competitive sensitivity to models where ambient dark matter particles carry small electric millicharges $\ll e$. Our calculations may also be useful in the characterization of noise in quantum computers coming from backgrounds of charged particles.

On Quanta of Information and Electromagnetic Fields. (arXiv:2107.02786v2 [quant-ph] UPDATED)

上午10:04 | | | Masroor H. S. Bukhari | | | quant-ph updates on arXiv.org |

We attempt to establish an equivalence of information and physical action, with the quanta (or packets of words) of information as possible sources of quantum fields (with a possible role in governing the interactions among those), similar to the quantum fields being the source of information. A physical model is formulated and reported here introducing the form and structure of these quanta of information, and their possible interactions with quantum fields. Information and quantum fields seem to be entangled with each other, and their underlying basis seems to have both a well-defined thermodynamic and probabilistic structure. The description of equivalent energy of a quantum of the electromagnetic field in terms of its information content, as well as an expression of signal power are provided. Various aspects of this problem and its possible implications and repercussions on our understanding of elementary quantum fields and their origin are discussed.

How a fake Kepler portrait became iconic. (arXiv:2108.02213v1 [physics.hist-ph])

上午10:04 | | | physics.hist-ph updates on arXiv.org |

Authors: Steven N. Shore, Václav Pavlík

For several decades a portrait of Johannes Kepler has been widely circulating among professional astronomers, scientific and academic institutions, and the general public. Despite its provenance and identification having been questioned in the early part of the last century, this painting has reached iconic status. We review its history from its first mention in the literature in the 1870s to a published but virtually unknown judgment of competent art experts of the 1920s that the work is in fact an early nineteenth century forgery. We display the painting in context with other more secure portraits and suggest that if it is based on anything, the painting may derive from the well known portrait from life of Michael M\”astlin. This correction takes on certain urgency since 2021 is the 450th anniversary of Kepler’s birth.

上午10:04 | | | physics.hist-ph updates on arXiv.org |

Authors: Artur Szczepanski

Classical objects have been excluded as subjects of the observed quantum properties, and the related problem of quantum objects nature has been suspended since the early days of Quantum Theory. Recent experiments show that the problem could be reasonably revisited. The outlined model indicates new issues, which could result from following and exploring the canonical idea of Dirac. Topological defects in solids are considered as an example. The aim is helping to grasp the underlying pre-theoretical new intuitions, which should replace the old ones attached to the background of classical physics.

Complexity and the Big Bang. (arXiv:2104.09626v3 [gr-qc] UPDATED)

上午10:04 | | | gr-qc updates on arXiv.org |

Authors: Hermann Nicolai

After a brief review of current scenarios for the resolution and/or avoidance of the Big Bang, an alternative hypothesis is put forward implying an infinite increase in complexity towards the initial singularity. This may result in an effective non-calculability which would present an obstruction to actually reaching the beginning of time. This proposal is motivated by the appearance of certain infinite-dimensional duality symmetries of indefinite Kac–Moody type in attempts to unify gravity with the fundamental matter interactions, and deeply rooted in properties of Einstein’s theory.

上午10:04 | | | gr-qc updates on arXiv.org |

Authors: Debaprasad Maity, Sourav Pal

Universe is believed to be born out of a quantum state. However, defining any observables associated the quantum properties and their possible observational possibilities in the present universe has gained significant interest recently. In this submission we propose quantum Poincare sphere measurement as an observable quantity which can give us hint of quantumness of the origin of primordial gravitational waves and large scale magnetic field. The Poincare sphere is defined in terms of power spectrum and quantum stokes operators associated with the polarization of those fields, which can be directly measured. To support our results we further explored the possible Bell violation test for a set of generalized pseudo spin operators defined in the polarization space of those fields.

Spacetime is material. (arXiv:2108.01712v1 [physics.hist-ph] CROSS LISTED)

上午10:04 | | | gr-qc updates on arXiv.org |

Authors: Luciano Combi

Space and time are central concepts for understanding our World. They are important ingredients at the core of every scientific theory and subject of intense debate in philosophy. Albert Einstein’s Special and General theories of Relativity showed that space and time blend in a single entity called spacetime. Even after a century of its conception, many questions about the nature of spacetime remain controversial. In this chapter, we analyze the ontological status of spacetime from a realistic and materialistic point of view. We start by outlining the well-known controversy between substantivalism and relationalism and the evolution of the debate with the appearance of General Relativity. We analyze how to interpret spacetime as a physical system and how to model its properties in a background-free theory where spacetime itself is dynamical. We discuss the concept of change, energy, and the ontology of spacetime events. In the last section, we review the mereology of spacetime and its relevance in cosmology.

2021年8月4日 星期三 上午8:00 | | | Latest Results for Synthese |

**Abstract**

In this paper I present a new perspective for interpreting the wavefunction as a non-material, non-epistemic, non-representational entity. I endorse a functional view according to which the wavefunction is defined by its roles in the theory. I argue that this approach shares some similarities with the nomological account of the wave function as well as with the pragmatist and epistemic approaches to quantum theory, while avoiding the major objections of these alternatives.

2021年8月2日 星期一 上午8:00 | | | Anders Malthe-Sørenssen | | | Nature Physics – Issue – nature.com science feeds |

Nature Physics, Published online: 02 August 2021; doi:10.1038/s41567-021-01312-1

Frictional sliding starts with a crack front propagating across an interface — a process that is well described by fracture mechanics. Experiments now show that the onset of crack formation is governed by physics that is yet to be fully understood.

Nucleation fronts ignite the interface rupture that initiates frictional motion

2021年8月2日 星期一 上午8:00 | | | Jay Fineberg | | | Nature Physics – Issue – nature.com science feeds |

Nature Physics, Published online: 02 August 2021; doi:10.1038/s41567-021-01299-9

Frictional motion between two surfaces in contact starts with the formation of nucleating rupture fronts. It is now shown that these emerge from nucleation fronts, which develop from a certain stress level onwards and with a characteristic velocity.

Intrinsic local distances: a mixed solution to Weyl’s tile argument

2021年8月1日 星期日 上午8:00 | | | Latest Results for Synthese |

**Abstract**

Weyl’s tile argument purports to show that there are no natural distance functions in atomistic space that approximate Euclidean geometry. I advance a response to this argument that relies on a new account of distance in atomistic space, called *the mixed account*, according to which *local distances* are primitive and other distances are derived from them. Under this account, atomistic space can approximate Euclidean space (and continuous space in general) very well. To motivate this account as a genuine solution to Weyl’s tile argument, I argue that this account is no less natural than the standard account of distance in continuous space. I also argue that the mixed account has distinctive advantages over Forrest’s (Synthese 103:327–354, 1995) account in response to Weyl’s tile argument, which can be considered as a restricted version of the mixed account.

Reliability of mathematical inference

2021年8月1日 星期日 上午8:00 | | | Latest Results for Synthese |

**Abstract**

Of all the demands that mathematics imposes on its practitioners, one of the most fundamental is that proofs ought to be correct. It has been common since the turn of the twentieth century to take correctness to be underwritten by the existence of formal derivations in a suitable axiomatic foundation, but then it is hard to see how this normative standard can be met, given the differences between informal proofs and formal derivations, and given the inherent fragility and complexity of the latter. This essay describes some of the ways that mathematical practice makes it possible to reliably and robustly meet the formal standard, preserving the standard normative account while doing justice to epistemically important features of informal mathematical justification.

2021年8月1日 星期日 上午8:00 | | | Latest Results for Synthese |

**Abstract**

The proposal that probabilistic inference and unconscious hypothesis testing are central to information processing in the brain has been steadily gaining ground in cognitive neuroscience and associated fields. One popular version of this proposal is the new theoretical framework of predictive processing or prediction error minimization (PEM), which couples unconscious hypothesis testing with the idea of ‘active inference’ and claims to offer a unified account of perception and action. Here we will consider one outstanding issue that still looms large at the core of the PEM framework: the lack of a clear criterion for distinguishing conscious states from unconscious ones. In order to fulfill the promise of becoming a unifying framework for describing and modeling cognition, PEM needs to be able to differentiate between conscious and unconscious mental states or processes. We will argue that one currently popular view, that the contents of conscious experience are determined by the ‘winning hypothesis’ (i.e. the one with the highest posterior probability, which determines the behavior of the system), falls short of fully accounting for conscious experience. It ignores the possibility that some states of a system can control that system’s behavior even though they are apparently not conscious (as evidenced by e.g. blindsight or subliminal priming). What follows from this is that the ‘winning hypothesis’ view does not provide a complete account of the difference between conscious and unconscious states in the probabilistic brain. We show how this problem (and some other related problems) for the received view can be resolved by augmenting PEM with Daniel Dennett’s multiple drafts model of consciousness. This move is warranted by the similar roles that attention and internal competition play in both the PEM framework and the multiple drafts model.

Macroscopic limit of quantum systems. (arXiv:2107.13594v1 [quant-ph])

2021年7月31日 星期六 上午9:55 | | | Janos Polonyi | | | quant-ph updates on arXiv.org |

The classical physics is approached from quantum mechanics in the macroscopic limit. The technical device to achieve this goal is the quantum version of the central limit theorem, derived for an observable at a given time and for the time-dependent expectation value of the coordinate. The emergence of the classical trajectory can be followed and the deterministic classical laws can be recovered in all practical purposes owing to the largeness of Avogadro’s number. The emergence of a classical trajectory is followed qualitatively in Wilson’s cloud chamber.

Locality and entanglement of indistinguishable particles. (arXiv:2107.13911v1 [quant-ph])

2021年7月31日 星期六 上午9:55 | | | Till Jonas Frederick Johann, Ugo Marzolino | | | quant-ph updates on arXiv.org |

Entanglement is one of the strongest quantum correlation, and is a key ingredient in fundamental aspects of quantum mechanics and a resource for quantum technologies. While entanglement theory is well settled for distinguishable particles, there are five inequivalent approaches to entanglement of indistinguishable particles. We analyse the different definitions of indistinguishable particle entanglement in the light of the locality notion. This notion is specified by two steps: i) the identification of subsystems by means of their local operators; ii) the requirement that entanglement represent correlations between the above subsets of operators. We prove that three of the aforementioned five entanglement definitions are incompatible with any locality notion defined as above.

Causal reappraisal of the quantum three box paradox. (arXiv:2107.13937v1 [quant-ph])

2021年7月31日 星期六 上午9:55 | | | Pawel Blasiak, Ewa Borsuk | | | quant-ph updates on arXiv.org |

Quantum three box paradox is a prototypical example of some bizarre predictions for intermediate measurements made on pre- and post-selected systems. Although in principle those effects can be explained by measurement disturbance, it is not clear what mechanisms are required to fully account for the observed correlations. In this paper, this paradox is scrutinised from the causal point of view. We consider an array of potential causal structures behind the experiment, eliminating those without enough explanatory power. This gives a means of differentiating between the various mechanisms in which measurement disturbance can propagate in the system. Specifically, we distinguish whether it is just the measurement outcome or the full measurement context that is required for the causal explanation of the observed statistics. We show that the latter is indispensable, but only when the full statistics is taken into account (which includes checking the third box too). Furthermore, we discuss the realism assumption which posits the existence of preexisting values revealed by measurements. It is shown that in this case measurement disturbance is necessary. Interestingly, without the realism assumption, the original version of the paradox (with just two boxes considered for inspection) can be explained without resorting to any measurement disturbance. These various results illustrate the richness of the paradox which is better appreciated from the causal perspective.

2021年7月31日 星期六 上午9:55 | | | Rhea Alexander, Si Gvirtz-Chen, David Jennings | | | quant-ph updates on arXiv.org |

Symmetry principles are fundamental in physics, and while they are well understood within Lagrangian mechanics, their impact on quantum channels has a range of open questions. The theory of asymmetry grew out of information-theoretic work on entanglement and quantum reference frames, and allows us to quantify the degree to which a quantum system encodes coordinates of a symmetry group. Recently a complete set of entropic conditions was found for asymmetry in terms of correlations relative to infinitely many quantum reference frames. However these conditions are difficult to use in practice and the physical implications unclear. Here we show that this set of conditions has extensive redundancy, and one can restrict to reference frames forming any closed surface in the state space that has the maximally mixed state in its interior. This in turn implies that asymmetry can be reduced to just a single entropic condition evaluated at the maximally mixed state. Contrary to intuition, this shows that we do not need macroscopic, classical reference frames to determine the asymmetry properties of a quantum system, but instead infinitesimally small frames suffice. Building on this analysis, we provide simple, closed conditions to estimate the minimal depolarization needed so as to make a given quantum state accessible under $G$-covariant quantum channels.

Ontology in quantum mechanics. (arXiv:2107.14191v1 [quant-ph])

2021年7月31日 星期六 上午9:55 | | | Gerard t Hooft | | | quant-ph updates on arXiv.org |

It is suspected that the quantum evolution equations describing the micro-world as we know it are of a special kind that allows transformations to a special set of basis states in Hilbert space, such that, in this basis, the evolution is given by elements of the permutation group. This would restore an ontological interpretation. It is shown how, at low energies per particle degree of freedom, almost any quantum system allows for such a transformation. This contradicts Bell’s theorem, and we emphasise why some of the assumptions made by Bell to prove his theorem cannot hold for the models studied here. We speculate how an approach of this kind may become helpful in isolating the most likely version of the Standard Model, combined with General Relativity. A link is suggested with black hole physics.

2021年7月31日 星期六 上午9:55 | | | Andrea Di Biagio, Pietro Donà, Carlo Rovelli | | | quant-ph updates on arXiv.org |

The operational formulations of quantum theory are drastically time oriented. However, to the best of our knowledge, microscopic physics is time-symmetric. We address this tension by showing that the asymmetry of the operational formulations does not reflect a fundamental time-orientation of physics. Instead, it stems from built-in assumptions about the $users$ of the theory. In particular, these formalisms are designed for predicting the future based on information about the past, and the main mathematical objects contain implicit assumption about the past, but not about the future. The main asymmetry in quantum theory is the difference between knowns and unknowns.

]]>上午9:55 | | | gr-qc updates on arXiv.org |

Authors: David Benisty, Denitsa Staicova

Dynamical Dark Energy (DDE) is a possible solution to the Hubble tension. This work analyses the combination of Baryon Acoustic Oscillation (BAO) data that include $19$ points from the range $0.11 \le z \le 2.40$ and additional points from the Cosmic Microwave Background (CMB) Distant Priors. We test equation of states with a Linear, CPL and a Logarithm dependence on the redshift. DDE seems to be stronger then the standard $\Lambda$CDM model statistically using different selection criteria. The result calls for new observations and stimulates the investigation of alternative theoretical models beyond the standard model. We also test the same dataset on the $\Omega_k$CDM model but for it, $\Lambda$CDM gives better statistical measures.

Holography of time machines. (arXiv:2107.14200v1 [hep-th])

上午9:55 | | | gr-qc updates on arXiv.org |

Authors: Roberto Emparan, Marija Tomašević

We use holography to examine the response of quantum fields to the appearance of closed timelike curves in a dynamically evolving background that initially does not contain them. For this purpose, we study a family of two-dimensional spacetimes that model very broad classes of wormhole time machines. The behavior of conformal theories in these spacetimes is then holographically described by three-dimensional AdS bulk geometries that we explicitly construct. The dual bulk spacetime is free from any divergences, but splits into two disconnected components, without and with CTCs, which are joined only through the boundary; this implies that passages across the chronology horizon are impossible for observers with finite energy. The bulk region with CTCs is a geodesically incomplete spacetime. Therefore, the bulk enforces the chronology protection principle in the most explicit manner — by completely separating the pathological part from the rest of the spacetime.

Are Points (Necessarily) Unextended?

上午4:21 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Ehrlich, Philip (2021) Are Points (Necessarily) Unextended? [Preprint]

2021年7月29日 星期四 下午6:00 | | | Máté Farkas, Maria Balanzó-Juandó, Karol Łukanowski, Jan Kołodyński, and Antonio Acín | | | PRL: General Physics: Statistical and Quantum Mechanics, Quantum Information, etc. |

Author(s): Máté Farkas, Maria Balanzó-Juandó, Karol Łukanowski, Jan Kołodyński, and Antonio Acín

Bell nonlocality is insufficient to ensure the security of a type of secure quantum-communications protocol known as DI-QKD.

[Phys. Rev. Lett. 127, 050503] Published Thu Jul 29, 2021

Unitary Interactions Do Not Yield Outcomes: Attempting to Model “Wigner’s Friend”

2021年7月26日 星期一 下午3:54 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Kastner, Ruth (2021) Unitary Interactions Do Not Yield Outcomes: Attempting to Model “Wigner’s Friend”. [Preprint]

2021年7月26日 星期一 下午3:51 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Verde, Clelia and Smolin, Lee (2021) Physics, time and qualia. [Preprint]

The Everett Interpretation: probability

2021年7月26日 星期一 下午3:51 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Saunders, Simon (2021) The Everett Interpretation: probability. [Preprint]

On the Relation of the Laws of Thermodynamics to Statistical Mechanics

2021年7月26日 星期一 下午3:50 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Myrvold, Wayne C. (2021) On the Relation of the Laws of Thermodynamics to Statistical Mechanics. [Preprint]

]]>上午10:54 | | | Francois-Igor Pris | | | quant-ph updates on arXiv.org |

We suggest a contextual realist interpretation of relational quantum mechanics. The principal point is a correct understanding of the concept of reality and taking into account the categorical distinction between the ideal and the real. Within our interpretation, consciousness of the observer does not play any metaphysical role. The proposed approach can also be understood as a return to the Copenhagen interpretation of quantum mechanics, corrected within the framework of contextual realism. The contextual realism allows one to get rid of the metaphysical problems encountered by various interpretations of quantum mechanics, including the relational one.

上午10:54 | | | Alex J. Schimmoller, Gerard McCaul, Hartmut Abele, Denys I. Bondar | | | quant-ph updates on arXiv.org |

Erik Verlinde’s theory of entropic gravity [arXiv:1001.0785], postulating that gravity is not a fundamental force but rather emerges thermodynamically, has garnered much attention as a possible resolution to the quantum gravity problem. Some have ruled this theory out on grounds that entropic forces are by nature noisy and entropic gravity would therefore display far more decoherence than is observed in ultra-cold neutron experiments. We address this criticism by modeling linear gravity acting on small objects as an open quantum system. In the strong coupling limit, when the model’s unitless free parameter $\sigma$ goes to infinity, the entropic master equation recovers conservative gravity. We show that the proposed master equation is fully compatible with the \textit{q}\textsc{Bounce} experiment for ultra-cold neutrons as long as $\sigma\gtrsim 250$ at $90\%$ confidence. Furthermore, the entropic master equation predicts energy increase and decoherence on long time scales and for large masses, phenomena which tabletop experiments could test. In addition, comparing entropic gravity’s energy increase to that of the Di\'{o}si-Penrose model for gravity induced decoherence indicates that the two theories are incompatible. These findings support the theory of entropic gravity, motivating future experimental and theoretical research.

Do gravitational waves confirm Hawking’s area law?. (arXiv:2107.10680v1 [physics.hist-ph])

上午10:54 | | | physics.hist-ph updates on arXiv.org |

Authors: Galina Weinstein

Recently an experiment has been performed for the purpose of “testing the area law with GW150914”. As the experimenters put it, the experiment presents “observational confirmation” of Hawking’s area law based on the GW150914 data. It is the purpose of this paper to philosophically examine the test of the area law and to show that the area law is not confirmable yet is falsifiable. Accordingly, the GW150914 data do not confirm Hawking’s area law. What has been tested with positive results was the hypothesis A3 > A1 + A2, where A3 = GW150914 remnant and A1 + A2 = GW150914 merger. But this single instance does not provide observational confirmation of Hawking’s area law.

Bell Nonlocality and the Reality of Quantum Wavefunction. (arXiv:2005.08577v4 [quant-ph] UPDATED)

上午10:54 | | | physics.hist-ph updates on arXiv.org |

Authors: Anandamay Das Bhowmik, Preeti Parashar, Manik Banik

Status of quantum wavefunction is one of the most debated issues in quantum foundations — whether it corresponds directly to the reality or just represents knowledge or information about some aspect of reality. In this letter we propose a {\it $\psi$-ontology} theorem that excludes a class of ontological explanations where quantum wavefunction is treated as mere information. Our result, unlike the acclaimed Pusey-Barrett-Rudolph’s theorem, does not presume the absence of holistic ontological properties for product quantum preparations. At the core of our derivation we utilize the seminal no-go result by John S. Bell that rules out any local realistic world view for quantum theory. We show that the observed phenomenon of quantum nonlocality cannot be incorporated in a class of $\psi$-epistemic models. Using the well known Clauser-Horne-Shimony-Holt inequality we obtain a threshold bound on the degree of epistemicity above which the ontological models are not compatible with quantum statistics.

Unifying theory of quantum state estimation using past and future information

上午10:54 | | | ScienceDirect Publication: Physics Reports |

Publication date: Available online 20 July 2021

**Source:** Physics Reports

Author(s): Areeya Chantasri, Ivonne Guevara, Kiarn T. Laverick, Howard M. Wiseman

Quantum state estimation for continuously monitored dynamical systems involves assigning a quantum state to an individual system at some time, conditioned on the results of continuous observations. The quality of the estimation depends on how much observed information is used and on how optimality is defined for the estimate. In this work, we consider problems of quantum state estimation where some of the measurement records are not available, but where the available records come from both before (past) and after (future) the estimation time, enabling better estimates than is possible using the past information alone. Past-future information for quantum systems has been used in various ways in the literature, in particular, the quantum state smoothing, the most-likely path, and the two-state vector and related formalisms. To unify these seemingly unrelated approaches, we propose a framework for partially observed quantum systems with continuous monitoring, wherein the first two existing formalisms can be accommodated, with some generalization. The unifying framework is based on state estimation with expected cost minimization, where the cost can be defined either in the space of the unknown record or in the space of the unknown true state. Moreover, we connect all three existing approaches conceptually by defining five new cost functions, and thus new types of estimators, which bridge the gaps between them. We illustrate the applicability of our method by calculating all seven estimators we consider for the example of a driven two-level system dissipatively coupled to bosonic baths. Our theory also allows connections to classical state estimation, which create further conceptual links between our quantum state estimators.

Hartle-Hawking state in the real-time formalism. (arXiv:2107.10271v1 [gr-qc])

上午10:54 | | | gr-qc updates on arXiv.org |

Authors: Atsushi Higuchi, William C. C. Lima

We study self-interacting massive scalar field theory in static spacetimes with a bifurcate Killing horizon and a wedge reflection. In this theory the Hartle-Hawking state is defined to have the $N$-point correlation functions obtained by analytically continuing those in the Euclidean theory, whereas the double KMS state is the pure state invariant under the Killing flow and the wedge reflection which is regular on the bifurcate Killing horizon and reduces to the thermal state at the Hawking temperature in each of the two static regions. We demonstrate in the Schwinger-Keldysh operator formalism of perturbation theory the equivalence between the Hartle-Hawking state and the double KMS state with the Hawking temperature, which was shown before by Jacobson in the path-integral framework.

Noether’s first theorem and the energy-momentum tensor ambiguity problem

上午2:00 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Baker, Mark Robert and Linnemann, Niels and Smeenk, Chris (2021) Noether’s first theorem and the energy-momentum tensor ambiguity problem. The Physics and Philosophy of Noether’s Theorems.

上午2:00 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Allori, Valia (2021) Wave-Functionalism. Synthese.

Understanding the Progress of Science

上午1:52 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

McCoy, C.D. (2021) Understanding the Progress of Science. [Preprint]

Testability and Viability: Is Inflationary Cosmology “Scientific”?

上午1:52 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Dawid, Richard and McCoy, C.D. (2021) Testability and Viability: Is Inflationary Cosmology “Scientific”? [Preprint]

The Constitution of Weyl’s Pure Infinitesimal World Geometry

上午1:51 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

McCoy, C.D. (2021) The Constitution of Weyl’s Pure Infinitesimal World Geometry. [Preprint]

What eliminative materialism isn’t

2021年7月23日 星期五 上午8:00 | | | Latest Results for Synthese |

**Abstract**

In this paper my aim is to get clearer on what eliminative materialism actually does and does not entail. I look closely at one cluster of views that is often described as a form of eliminativism in contemporary philosophy and cognitive science and try to show that this characterization is a mistake. More specifically, I look at conceptions of eliminativism recently endorsed by writers such as Edouard Machery (2009), Paul Griffiths (1997), Valerie Hardcastle (1999) and others, and argue that although these views do endorse the elimination of something, they offer only what I will call a sort of category dissolution, and should be treated as something altogether different from traditional eliminativism. Spelling out the main contrast(s) between eliminative materialism proper and this alternative view, and defending the need to keep them distinct, is my primary objective. As I show, a central irony is that proponents of the problematic outlook often insist that divergent things should not be classified together under a single label. By characterizing their own views as a form of eliminativism, they commit a fundamental error that they themselves argue should not be made. While my focus here is on eliminative materialism, the error I intend to highlight appears across various discussions about alleged eliminativism of all sorts of things.

2021年7月22日 星期四 上午8:00 | | | Latest Results for Synthese |

**Abstract**

The counterfactual and regularity theories are universal accounts of causation. I argue that these should be generalized to produce *local* accounts of causation. A hallmark of universal accounts of causation is the assumption that apparent variation in causation between locations must be explained by differences in background causal conditions, by features of the causal-nexus or causing-complex. The local account of causation presented here rejects this assumption, allowing for genuine variation in causation to be explained by differences in location. I argue that local accounts of causation are plausible, and have pragmatic, empirical and theoretical advantages over universal accounts. I then report on the use of presheaves as models of local causation. The use of presheaves as models of local variation has precedents in algebraic geometry, category theory and physics; they are here used as models of local causal variation. The paper presents this idea as stemming from an approach using presheaves as models of local truth. Finally, I argue that a proper balance between universal and local causation can be assuaged by moving from presheaves to fully-fledged sheaf models.

Consciousness and the Laws of Physics

2021年7月20日 星期二 上午5:03 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Carroll, Sean M. (2021) Consciousness and the Laws of Physics. [Preprint]

]]>下午5:48 | | | W.M. Stuckey, Timothy McDevitt, Michael Silberstein | | | quant-ph updates on arXiv.org |

Quantum information theorists have created axiomatic reconstructions of quantum mechanics (QM) that are very successful at identifying precisely what distinguishes quantum probability theory from classical and more general probability theories in terms of information-theoretic principles. Herein, we show how two such principles, i.e., “Existence of an Information Unit” and “Continuous Reversibility,” map to the relativity principle as it pertains to the invariant measurement of Planck’s constant h for Stern-Gerlach (SG) spin measurements in spacetime in exact analogy to the relativity principle as it pertains to the invariant measurement of the speed of light c for special relativity (SR). Essentially, quantum information theorists have extended Einstein’s use of the relativity principle from the boost invariance of measurements of c to include the SO(3) invariance of measurements of h between different reference frames of mutually complementary spin measurements via the principle of “Information Invariance & Continuity.” Consequently, the “average-only” conservation represented by the Bell states that is responsible for the Tsirelson bound and the exclusion of the no-signalling, “superquantum” Popescu-Rohrlich joint probabilities is understood to result from conservation per Information Invariance & Continuity between different reference frames of mutually complementary measurements, and this maps to conservation per the relativity principle in spacetime. Thus, the axiomatic reconstructions of QM have succeeded in producing a principle account of QM that is every bit as robust as the postulates of SR, revealing a still broader role for the relativity principle in the foundations of physics.

下午5:48 | | | Raphael F. Ribeiro | | | quant-ph updates on arXiv.org |

Despite the potential paradigm breaking capability of microcavities to control chemical processes, the extent to which photonic devices change properties of molecular materials is still unclear, in part due to challenges in modeling hybrid light-matter excitations delocalized over many length scales. We overcome these challenges for a photonic wire under strong coupling with a molecular ensemble. Our simulations provide a detailed picture of the effect of photonic wires on spectral and transport properties of a disordered molecular material. We find stronger changes to the probed molecular observables when the cavity is redshifted relative to the molecules and energetic disorder is weak. These trends are expected to hold also in higher-dimensional cavities, but are not captured with theories that only include a single cavity-mode. Therefore, our results raise important issues for future experiments and model building focused on unraveling new ways to manipulate chemistry with optical cavities.

The Quantum Mechanics Swampland. (arXiv:2012.11606v2 [hep-th] UPDATED)

下午5:48 | | | Aditya Parikh | | | quant-ph updates on arXiv.org |

We investigate non-relativistic quantum mechanical potentials between fermions generated by various classes of QFT operators and evaluate their singularity structure. These potentials can be generated either by four-fermion operators or by the exchange of a scalar or vector mediator coupled via renormalizable or non-renormalizable operators. In the non-relativistic regime, solving the Schr\”odinger equation with these potentials provides an accurate description of the scattering process. This procedure requires providing a set of boundary conditions. We first recapitulate the procedure for setting the boundary conditions by matching the first Born approximation in quantum mechanics to the tree-level QFT approximation. Using this procedure, we show that the potentials are nonsingular, despite the presence of terms proportional to $r^{-3}$ and $\nabla_{i}\nabla_{j}\delta^{3}(\vec{r})$. This surprising feature leads us to propose the \emph{Quantum Mechanics Swampland}, in which the Landscape consists of non-relativistic quantum mechanical potentials that can be UV completed to a QFT, and the Swampland consists of pathological potentials which cannot. We identify preliminary criteria for distinguishing potentials which reside in the Landscape from those that reside in the Swampland. We also consider extensions to potentials in higher dimensions and find that Coulomb potentials are nonsingular in an arbitrary number of spacetime dimensions.

下午5:48 | | | physics.hist-ph updates on arXiv.org |

Authors: Karl-Erik Eriksson

At the time of publication of H. Everett’s Relative-State Formulation (1957) and DeWitt’s Many-Worlds Interpretation (1970), quantum mechanics was available in a more modern and adequate version than the one used by these authors. We show that with the more modern quantum theory, quantum measurement could have been analyzed along more conventional lines in a one-world cosmology. Bell criticized the Everett-DeWitt theory quite sharply in 1987 but this seems not to have affected the acceptance of the old quantum mechanics as the framework for analysis of measurement.

下午5:48 | | | physics.hist-ph updates on arXiv.org |

Authors: Indrajit Sen

A recent proposal for a superdeterministic account of quantum mechanics, named Invariant-set theory, appears to bring ideas from several diverse fields like chaos theory, number theory and dynamical systems to quantum foundations. However, a clear cut hidden-variable model has not been developed, which makes it difficult to assess the proposal from a quantum foundational perspective. In this article, we first build a hidden-variable model based on the proposal, and then critically analyse several aspects of the proposal using the model. We show that several arguments related to counter-factual measurements, nonlocality, non-commutativity of quantum observables, measurement independence etcetera that appear to work in the proposal fail when considered in our model. We further show that our model is not only superdeterministic but also nonlocal, with an ontic quantum state. Lastly, we apply the analysis developed in a previous work (Proc. R. Soc. A, 476(2243):20200214, 2020) to illustrate the issue of superdeterministic conspiracy in the model. Our results lend further support to the view that superdeterminism is unlikely to solve the puzzle posed by the Bell correlations.

下午5:48 | | | gr-qc updates on arXiv.org |

Authors: Suddhasattwa Brahma, Arjun Berera, Jaime Calderón-Figueroa

Although the paradigm of inflation has been extensively studied to demonstrate how macroscopic inhomogeneities in our universe originate from quantum fluctuations, most of the established literature ignores the crucial role that entanglement between the modes of the fluctuating field plays in its observable predictions. In this paper, we import techniques from quantum information theory to reveal hitherto undiscovered predictions for inflation which, in turn, signals how quantum entanglement across cosmological scales can affect large scale structure. Our key insight is that observable long-wavelength modes must be part of an open quantum system, so that the quantum fluctuations can decohere in the presence of an environment of short-wavelength modes. By assuming the simplest model of single-field inflation, and considering the leading order interaction term from the gravitational action, we derive a universal lower bound on the observable effect of such inescapable entanglement.

On the re-interpretation of Wheeler-DeWitt equation. (arXiv:1910.13217v2 [gr-qc] UPDATED)

下午5:48 | | | gr-qc updates on arXiv.org |

Authors: Avadhut V. Purohit

I have shown that the field defined by the Wheeler-DeWitt equation for pure gravity is not a standard gravitational field. This field has some features that are common to the matter fields. The re-interpretation leads to the geometrization of quantum theory..

Creativity and Modelling the Measurement Process of the Higgs self-coupling at the LHC and HL-LHC

下午3:45 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Ritson, Sophie (2021) Creativity and Modelling the Measurement Process of the Higgs self-coupling at the LHC and HL-LHC. [Preprint]

A reply to Rovelli’s response to our “Assessing Relational Quantum Mechanics”

2021年7月14日 星期三 下午2:28 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Muciño, Ricardo and Okon, Elias and Sudarsky, Daniel (2021) A reply to Rovelli’s response to our “Assessing Relational Quantum Mechanics”. [Preprint]

]]>Sebastian Fortin & Olimpia Lombardi

**Abstract**

In a recent article entitled “The problem of molecular structure just is the measurement problem”, Alexander Franklin and Vanessa Seifert argue that insofar as the quantum measurement problem is solved, the problems of molecular structure are resolved as well. The purpose of the present article is to show that such a claim is too optimistic. Although the solution of the quantum measurement problem is relevant to how the problem of molecular structure is faced, such a solution is not sufficient to account for the structure of molecules as understood in the field of chemistry.

Qubits are not observers — a no-go theorem. (arXiv:2107.03513v1 [quant-ph])

上午9:32 | | | Časlav Brukner | | | quant-ph updates on arXiv.org |

The relational approach to quantum states asserts that the physical description of quantum systems is always relative to something or someone. In relational quantum mechanics (RQM) it is relative to other quantum systems, in the (neo-)Copenhagen interpretation of quantum theory to measurement contexts, and in QBism to the beliefs of the agents. In contrast to the other two interpretations, in RQM any interaction between two quantum systems counts as a “measurement”, and the terms “observer” and “observed system” apply to arbitrary systems. We show, in the form of a no-go theorem, that in RQM the physical description of a system relative to an observer cannot represent knowledge about the observer in the conventional sense of this term. The problem lies in the ambiguity in the choice of the basis with respect to which the relative states are to be defined in RQM. In interpretations of quantum theory where observations play a fundamental role, the problem does not arise because the experimental context defines a preferred basis.

上午9:32 | | | Christian Ufrecht, Albert Roura, Wolfgang P. Schleich | | | quant-ph updates on arXiv.org |

Light-pulse atom interferometers are highly sensitive to inertial and gravitational effects. As such they are promising candidates for tests of gravitational physics. In this article the state-of-the-art and proposals for fundamental tests of gravity are reviewed. They include the measurement of the gravitational constant $G$, tests of the weak equivalence principle, direct searches of dark energy and gravitational-wave detection. Particular emphasis is put on long-time interferometry in microgravity environments accompanied by an enormous increase of sensitivity. In addition, advantages as well as disadvantages of Bose-Einstein condensates as atom sources are discussed.

A Quantum Engineer’s Guide to Superconducting Qubits. (arXiv:1904.06560v5 [quant-ph] UPDATED)

上午9:32 | | | Philip Krantz, Morten Kjaergaard, Fei Yan, Terry P. Orlando, Simon Gustavsson, William D. Oliver | | | quant-ph updates on arXiv.org |

The aim of this review is to provide quantum engineers with an introductory guide to the central concepts and challenges in the rapidly accelerating field of superconducting quantum circuits. Over the past twenty years, the field has matured from a predominantly basic research endeavor to one that increasingly explores the engineering of larger-scale superconducting quantum systems. Here, we review several foundational elements — qubit design, noise properties, qubit control, and readout techniques — developed during this period, bridging fundamental concepts in circuit quantum electrodynamics (cQED) and contemporary, state-of-the-art applications in gate-model quantum computation.

Cellular automata in operational probabilistic theories. (arXiv:1911.11216v4 [quant-ph] UPDATED)

上午9:32 | | | Paolo Perinotti | | | quant-ph updates on arXiv.org |

The theory of cellular automata in operational probabilistic theories is developed. We start introducing the composition of infinitely many elementary systems, and then use this notion to define update rules for such infinite composite systems. The notion of causal influence is introduced, and its relation with the usual property of signalling is discussed. We then introduce homogeneity, namely the property of an update rule to evolve every system in the same way, and prove that systems evolving by a homogeneous rule always correspond to vertices of a Cayley graph. Next, we define the notion of locality for update rules. Cellular automata are then defined as homogeneous and local update rules. Finally, we prove a general version of the wrapping lemma, that connects CA on different Cayley graphs sharing some small-scale structure of neighbourhoods.

上午9:32 | | | Arkady Bolotin | | | quant-ph updates on arXiv.org |

The traditional analysis of the basic version of the double-slit experiment leads to the conclusion that wave-particle duality is a fundamental fact of nature. However, such a conclusion means to imply that we are not only required to have two contradictory pictures of reality but also compelled to abandon the objectiveness of the truth values, “true” and “false”. Yet, even if we could accept wave-like behavior of quantum particles as the best explanation for the build-up of an interference pattern in the double-slit experiment, without the objectivity of the truth values we would never have certainty regarding any statement about the world. The present paper discusses ways to reconcile the correct description of the double-slit experiment with the objectiveness of “true” and “false”.

上午9:32 | | | Kazuto Oshima | | | quant-ph updates on arXiv.org |

We indicate that there are points to keep in mind in utilizing quantum states prepared by the adiabatic quantum computation. Even if an instantaneous expectation value of a physical quantity for the adiabatically prepared quantum state is close to an expectation value for the true vacuum, this does not assure us that the prepared vacuum is close to the true vacuum. In general time average of the expectation value tend to systematically differ from the true value. Using a simple model we discuss how to diminish this systematic difference.

上午9:32 | | | physics.hist-ph updates on arXiv.org |

Authors: Richard de Grijs (Macquarie University, Sydney, Australia)

Despite frequent references in modern reviews to a seventeenth-century Venetian longitude prize, only a single, circumstantial reference to the alleged prize is known from contemporary sources. Edward Harrison’s scathing assessment of the conditions governing the award of an alleged Venetian longitude prize simultaneously disparages the rewards offered by the Dutch States General. However, the latter had long run its course by 1696, the year of the citation, thus rendering Harrison’s reference unreliable. Whereas other longitude awards offered by the leading European maritime nations attracted applicants from far and wide, often accompanied by extensive, self-published pamphlets, the alleged Venetian prize does not seem to have been subject to similar hype. The alleged existence of seventeenth-century Venetian award is particularly curious, because the city’s fortune was clearly in decline, and longitude determination on the open seas does not appear to have been a priority; the city’s mariners already had access to excellent “portolan” charts. It is therefore recommended that authors refrain from referring to a potentially phantom Venetian longitude prize in the same context as the major sixteenth- to eighteenth-century European awards offered by the dominant sea-faring nations.

上午9:32 | | | physics.hist-ph updates on arXiv.org |

Authors: Leander Vignero, Sylvia Wenmackers

In this paper, we take a fresh look at three Popperian concepts: riskiness, falsifiability, and truthlikeness (or verisimilitude) of scientific hypotheses or theories. First, we make explicit the dimensions that underlie the notion of riskiness. Secondly, we examine if and how degrees of falsifiability can be defined, and how they are related to various dimensions of the concept of riskiness as well as the experimental context. Thirdly, we consider the relation of riskiness to (expected degrees of) truthlikeness. Throughout, we pay special attention to probabilistic theories and we offer a tentative, quantitative account of verisimilitude for probabilistic theories.

上午3:03 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Potochnik, Angela (2021) Truth and reality: How to be a scientific realist without believing scientific theories should be true. [Preprint]

Approaching probabilistic laws

2021年7月9日 星期五 上午8:00 | | | Latest Results for Synthese |

**Abstract**

In the general problem of verisimilitude, we try to define the distance of a statement from a target, which is an informative truth about some domain of investigation. For example, the target can be a state description, a structure description, or a constituent of a first-order language (Sect. 1). In the problem of legisimilitude, the target is a deterministic or universal law, which can be expressed by a nomic constituent or a quantitative function involving the operators of physical necessity and possibility (Sect. 2). The special case of legisimilitude, where the target is a probabilistic law (Sect. 3), has been discussed by Roger Rosenkrantz (*Synthese*, 1980) and Ilkka Niiniluoto (*Truthlikeness*, 1987, Ch. 11.5). Their basic proposal is to measure the distance between two probabilistic laws by the Kullback–Leibler notion of divergence, which is a semimetric on the space of probability measures. This idea can be applied to probabilistic laws of coexistence and laws of succession, and the examples may involve discrete or continuous state spaces (Sect. 3). In this paper, these earlier studies are elaborated in four directions (Sect. 4). First, even though deterministic laws are limiting cases of probabilistic laws, the target-sensitivity of truthlikeness measures implies that the legisimilitude of probabilistic laws is not easily reducible to the deterministic case. Secondly, the Jensen-Shannon divergence is applied to mixed probabilistic laws which entail some universal laws. Thirdly, a new class of distance measures between probability distributions is proposed, so that their horizontal differences are taken into account in addition to vertical ones (Sect. 5). Fourthly, a solution is given for the epistemic problem of estimating degrees of probabilistic legisimilitude on the basis of empirical evidence (Sect. 6).

Formulations of Classical Mechanics

2021年7月8日 星期四 下午12:36 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

North, Jill (2019) Formulations of Classical Mechanics. [Preprint]

Is Electromagnetic Field Momentum Due to the Flow of Field Energy?

2021年7月8日 星期四 上午5:43 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Johns, Oliver Davis (2021) Is Electromagnetic Field Momentum Due to the Flow of Field Energy? [Preprint]

Can machines think? The controversy that led to the Turing test, 1946-1950

2021年7月8日 星期四 上午5:43 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Gonçalves, Bernardo (2021) Can machines think? The controversy that led to the Turing test, 1946-1950. [Preprint]

Relational Quantum Mechanics and the PBR Theorem: A Peaceful Coexistence

2021年7月8日 星期四 上午2:06 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Oldofredi, Andrea and Calosi, Claudio (2021) Relational Quantum Mechanics and the PBR Theorem: A Peaceful Coexistence. [Preprint]

Understanding Physics: ‘What?’, ‘Why?’, and ‘How?’

2021年7月8日 星期四 上午2:05 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Hubert, Mario (2021) Understanding Physics: ‘What?’, ‘Why?’, and ‘How?’. [Preprint]

Relativistic Constraints on Interpretations of Quantum Mechanics

2021年7月6日 星期二 下午2:08 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Myrvold, Wayne C. (2020) Relativistic Constraints on Interpretations of Quantum Mechanics. [Preprint]

2021年7月6日 星期二 上午8:00 | | | Latest Results for Synthese |

**Abstract**

Representations, in particular diagrammatic representations, allegedly contribute to new insights in mathematics. Here I explore the phenomenon of a “free ride” and to what extent it occurs in mathematics. A free ride, according to Shimojima (Artif Intell Rev 15: 5–27, 2001), is the property of some representations that whenever certain pieces of information have been represented then a new piece of consequential information can be read off for free. I will take Shimojima’s (informal) framework as a tool to analyse the occurrence and properties of them. I consider a number of different examples from mathematical practice that illustrate a variety of uses of free rides in mathematics. Analysing these examples I find that mathematical free rides are sometimes based on syntactic and semantic properties of diagrams.

Structures in the terms of the Vlasov equation observed at Earth’s magnetopause

2021年7月5日 星期一 上午8:00 | | | R. B. Torbert | | | Nature Physics – Issue – nature.com science feeds |

Nature Physics, Published online: 05 July 2021; doi:10.1038/s41567-021-01280-6

Insights into the structure of the Vlasov equation that governs the evolution of collisionless plasmas from observations have been limited. Now the spatial gradient term for electrons is analysed with recent data from the MMS mission.

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