上午2:21 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Pruss, Dasha (2021) Mechanical Jurisprudence and Domain Distortion: How Predictive Algorithms Warp the Law. [Preprint]

Approaching probabilistic and deterministic nomic truths in an inductive probabilistic way

上午2:21 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Kuipers, Theo A.F. (2021) Approaching probabilistic and deterministic nomic truths in an inductive probabilistic way. [Preprint]

The Philosophy of the Future of Science

上午2:16 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Virmajoki, Veli (2021) The Philosophy of the Future of Science. [Preprint]

What Theoretical Equivalence Could Not Be

上午2:12 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Teitel, Trevor (2021) What Theoretical Equivalence Could Not Be. [Preprint]

Physics and Metaphysics of Wigner’s Friends: Even Performed Premeasurements Have No Results

2021年4月2日 星期五 下午6:00 | | | Marek Żukowski and Marcin Markiewicz | | | PRL: General Physics: Statistical and Quantum Mechanics, Quantum Information, etc. |

Author(s): Marek Żukowski and Marcin Markiewicz

“The unambiguous account of proper quantum phenomena must, in principle, include a description of all relevant features of experimental arrangement” (Bohr). The measurement process is composed of premeasurement (quantum correlation of the system with the pointer variable) and an irreversible decoher…

[Phys. Rev. Lett. 126, 130402] Published Fri Apr 02, 2021

2021年4月2日 星期五 上午10:12 | | | H. Moaiery, A. Chenani, A. Hakimifard, N. Tahmasebi | | | quant-ph updates on arXiv.org |

In this work, the general form of $2\times2$ Dirac matrices for 2+1 dimension is found. In order to find this general representation, all relations among the elements of the matrices and matrices themselves are found,and the generalized Lorentz transform matrix is also found under the effect of the general representation of Dirac matrices. As we know, the well known equation of Dirac, $ \left( i\gamma^{\mu}\partial_{\mu}-m\right) \Psi=0 $, is consist of matrices of even dimension known as the general representation of Dirac matrices or Dirac matrices. Our motivation for this study was lack of the general representation of these matrices despite the fact that more than nine decades have been passed since the discovery of this well known equation. Everyone has used a specific representation of this equation according to their need; such as the standard representation known as Dirac-Pauli Representation, Weyl Representation or Majorana representation. In this work, the general form which these matrices can have is found once for all.

Why is AI hard and Physics simple?. (arXiv:2104.00008v1 [cs.LG])

2021年4月2日 星期五 上午10:12 | | | physics.hist-ph updates on arXiv.org |

Authors: Daniel A. Roberts

We discuss why AI is hard and why physics is simple. We discuss how physical intuition and the approach of theoretical physics can be brought to bear on the field of artificial intelligence and specifically machine learning. We suggest that the underlying project of machine learning and the underlying project of physics are strongly coupled through the principle of sparsity, and we call upon theoretical physicists to work on AI as physicists. As a first step in that direction, we discuss an upcoming book on the principles of deep learning theory that attempts to realize this approach.

Time Symmetry in Operational Theories. (arXiv:2104.00071v1 [quant-ph])

2021年4月2日 星期五 上午10:12 | | | gr-qc updates on arXiv.org |

Authors: Lucien Hardy

The standard operational probabilistic framework (within which we can formulate Operational Quantum Theory) is time asymmetric. This is clear because the conditions on allowed operations are time asymmetric. It is odd, though, because Schoedinger’s equation is time symmetric and probability theory does not care about time direction. In this work we provide a time symmetric framework for operational theories in general and for Quantum Theory in particular.

The clearest expression of the time asymmetry of standard Operational Quantum Theory is that the deterministic effect is unique – meaning there is only one way to ignore the future – while deterministic (i.e normalised) states are not unique. In this paper, this time asymmetry is traced back to a time asymmetric understanding of the most basic elements of an operational theory – namely the operations (or boxes) out of which circuits are built. We modify this allowing operations to have classical incomes as well as classical outcomes on these operations. We establish a time symmetric operational framework for circuits built out of operations. In particular, we demand that the probability associated with a circuit is the same whether we calculate it forwards in time or backwards in time. We do this by imposing various double properties. These are properties wherein a forward in time and a backward in time version of the same property are required. In this paper we provide a new causality condition which we call double causality.

The topological order of the space. (arXiv:2104.00227v1 [gr-qc])

2021年4月2日 星期五 上午10:12 | | | gr-qc updates on arXiv.org |

Authors: Jingbo Wang

Topological order is a new type order that beyond Landau’s symmetry breaking theory. The topological entanglement entropy provides a universal quantum number to characterize the topological order in a system. The topological entanglement entropy of the BTZ black hole was calculated and found that it coincides with that for fractional quantum Hall state. So the BTZ black holes have the same topological order with the fractional quantum Hall state. We conjecture that black holes in higher dimensions also have topological orders. Next we want to study the topological order of ordinary spaces which can be described by spin network states in loop quantum gravity. We advise to bring in the methods and results in string-net condensation to loop quantum gravity to solve some difficult problems.

A peek outside our Universe. (arXiv:2104.00521v1 [gr-qc])

2021年4月2日 星期五 上午10:12 | | | gr-qc updates on arXiv.org |

Authors: Enrique Gaztanaga, Pablo Fosalba

According to General Relativity (GR) a universe with a cosmological constant, Lambda, like ours, is trapped inside an event horizon r< sqrt(3/Lambda). What is outside? We show, using Israel (1967) junction conditions, that there could be a different universe outside. Our Universe looks like a Black Hole for an outside observer. Outgoing radial null geodesics can not escape our universe, but incoming photons can enter and leave an imprint on our CMB sky. We present a picture of such a fossil record from the analysis of CMB maps that agrees with the Black Hole universe predictions but challenge our understanding of the origin of the primordial universe.

Quantum Measurement of Space-Time Events. (arXiv:2011.11541v3 [quant-ph] UPDATED)

2021年4月2日 星期五 上午10:12 | | | gr-qc updates on arXiv.org |

Authors: Dorje C. Brody, Lane P. Hughston

The phase space of a relativistic system can be identified with the future tube of complexified Minkowski space. As well as a complex structure and a symplectic structure, the future tube, seen as an eight-dimensional real manifold, is endowed with a natural positive-definite Riemannian metric that accommodates the underlying geometry of the indefinite Minkowski space metric, together with its symmetry group. A unitary representation of the 15-parameter group of conformal transformations can then be constructed that acts upon the Hilbert space of square-integrable holomorphic functions on the future tube. These structures are enough to allow one to put forward a quantum theory of phase-space events. In particular, a theory of quantum measurement can be formulated in a relativistic setting, based on the use of positive operator valued measures, for the detection of phase-space events, hence allowing one to assign probabilities to the outcomes of joint space-time and four-momentum measurements in a manifestly covariant framework. This leads to a localization theorem for phase-space events in relativistic quantum theory, determined by the associated Compton wavelength.

Maxwellian mirages in general relativity. (arXiv:2012.08077v2 [gr-qc] UPDATED)

2021年4月2日 星期五 上午10:12 | | | gr-qc updates on arXiv.org |

Authors: L.L. Williams, N. Inan

Maxwellian approximations to linear general relativity are revisited in light of relatively recent results on the degrees of freedom in the linear gravitational field. The well-known Maxwellian formalism obtained in harmonic coordinates is compared with a Maxwellian formalism obtained under a coordinate choice where each of the metric components corresponds to each of the coordinate-invariant degrees of freedom of the linear gravitational field. The coordinate freedom of general relativity can be exploited to cast the field equations into Maxwellian form, but such forms can be mere mirages of the coordinate choice — mirages such as vector gravitational waves. A coordinate choice that yields perfectly-Maxwellian field equations, will yield a force equation that is not Lorentzian. If field definitions are chosen to obtain Lorentz-like terms in the force equation, then Maxwellian forms are compromised in the field equations. Many treatments of gravito-electromagnetism will make inconsistent ordering choices between the field equations and force equations, or else truncate terms of relevant order from the force equation. Often such mistakes reflect an attempt to force exact Maxwellian analogs simultaneously in both the field equations and the force equation, with the result that terms dropped are as large as those kept.

2021年4月2日 星期五 上午8:00 | | | Jan Ryckebusch | | | Nature Physics – Issue – nature.com science feeds |

Nature Physics, Published online: 02 April 2021; doi:10.1038/s41567-021-01224-0

A detailed analysis of a nucleon-knockout experiment has put forward a methodological roadmap for overcoming ambiguities in the interpretation of the data — promising access to the nuclear wave functions in unstable nuclei.

2021年4月1日 星期四 上午8:00 | | | Arianna Bottinelli | | | Nature Physics – Issue – nature.com science feeds |

Nature Physics, Published online: 01 April 2021; doi:10.1038/s41567-021-01220-4

Unreal art and hidden physics

Mind-body interaction and modern physics

2021年4月1日 星期四 上午2:39 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Anastopoulos, Charis (2020) Mind-body interaction and modern physics. [Preprint]

Noether’s Theorems and Energy in General Relativity

2021年4月1日 星期四 上午2:36 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

De Haro, Sebastian (2021) Noether’s Theorems and Energy in General Relativity. [Preprint]

QBism and the Limits of Scientific Realism

2021年3月30日 星期二 下午1:11 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Glick, David (2021) QBism and the Limits of Scientific Realism. [Preprint]

2021年3月28日 星期日 上午3:50 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Vessonen, Elina (2021) Representation in Measurement. [Preprint]

Were EPR correct after all; did Bell miss a point

2021年3月28日 星期日 上午3:49 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Thompson, John F (2021) Were EPR correct after all; did Bell miss a point. UNSPECIFIED.

]]>The circles theory tries to explain the complex functioning of the harmonic oscillator. It is a non-quantum mechanics theory, but it shows a good similarity with the forms of equations of the relativistic quantum mechanics. The Circles Theory explains the association of the wave and the point that corresponds with the wave and particle of quantum mechanics. According to the circular motions of an individual system, a fluid model for a huge number of the circular system is expected to be formed. Then, a wave of fluid may appear. So, a real wave of fluid-type is seen due to the circular motion in addition to the wave associated with the point or the particle. In this article, the double slit experiment has been explained in accordance with the circles theory. According to the circles theory, the double slit experiment shows that this fluid-like wave is responsible for the interference pattern, whereas the associate wave is responsible for the uncertain location of the particle on the screen. On the other hand, the observation of the fluid may destroy the formulation of the wave of fluid. If this happens, then the interference disappears, but a pattern of shout bullets appears. The rolling circles model of the circles theory cannot be investigated excrementally. This explanation of the double slit experiment may prove the existence of this rolling circles system.

]]>The quantum measurement problem is the most fundamental question of all: How the ghostly quantum mechanical coexistence of many mutually incompatible possibilities result in the concrete reality of the normal world, even though we and our measuring instruments are all made of atoms obeying quantum mechanics. In this brief article we lay down the criteria for such a mechanism.

]]>By treating an electron as its own Electromagnetic (EM) field and generalizing the Lorentz force to be the field force between the electron’s EM field and its external EM field, it is proved that the radiating field and the Coulomb-like field of an accelerated electron do interact, with the radiating field provides the exact momentum change needed by the Coulomb-like field. Thus, the radiating field of an accelerated electron fulfills the role of virtual photon in Quantum Electrodynamics (QED). By treating the radiating field as virtual photon, it is closely examined how the virtual photon is emitted and absorbed by the electron, and how the condition which leads to infinity in QED can be removed. Consequently, the necessity of Renormalization is removed. The conventional formula of the radiation power by an accelerated electron is questioned, and a new formula is given. Two experiments to test the new formula are proposed. When the electron is treated as its own EM field and its location is the center of mass of its EM field, it is explained why an electron does not radiate when it free-falls under the gravity.

]]>上午1:14 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Read, James and Le Bihan, Baptiste (2021) The Landscape and the Multiverse: What’s the Problem? [Preprint]

The Sheaf-Theoretic Structure of Definite Causality. (arXiv:2103.13771v1 [quant-ph])

2021年3月26日 星期五 下午4:23 | | | Stefano Gogioso, Nicola Pinzani | | | quant-ph updates on arXiv.org |

We extend the sheaf-theoretic framework for non-locality by Abramsky and Brandenburger to deal with operational scenarios in the presence of arbitrary definite causal orders.

2021年3月26日 星期五 下午4:23 | | | Joscha Henheik, Stefan Teufel | | | quant-ph updates on arXiv.org |

We show that recent results on adiabatic theory for interacting gapped many-body systems on finite lattices remain valid in the thermodynamic limit. More precisely, we prove a generalised super-adiabatic theorem for the automorphism group describing the infinite volume dynamics on the quasi-local algebra of observables. The key assumption is the existence of a sequence of gapped finite volume Hamiltonians which generates the same infinite volume dynamics in the thermodynamic limit. Our adiabatic theorem holds also for certain perturbations of gapped ground states that close the spectral gap (so it is an adiabatic theorem also for resonances and in this sense `generalised’), and it provides an adiabatic approximation to all orders in the adiabatic parameter (a property often called `super-adiabatic’). In addition to existing results for finite lattices, we also perform a resummation of the adiabatic expansion and allow for observables that are not strictly local. Finally, as an application, we prove the validity of linear and higher order response theory for our class of perturbations also for infinite systems.

While we consider the result and its proof as new and interesting in itself, they also lay the foundation for the proof of an adiabatic theorem for systems with a gap only in the bulk, which will be presented in a follow-up article.

2021年3月26日 星期五 下午4:23 | | | Joscha Henheik, Stefan Teufel | | | quant-ph updates on arXiv.org |

We prove a generalised super-adiabatic theorem for extended fermionic systems assuming a spectral gap only in the bulk. More precisely, we assume that the infinite system has a unique ground state and that the corresponding GNS-Hamiltonian has a spectral gap above its eigenvalue zero. Moreover, we show that a similar adiabatic theorem also holds in the bulk of finite systems up to errors that vanish faster than any inverse power of the system size, although the corresponding finite volume Hamiltonians need not have a spectral gap.

Decoherence, Collapse, and Conservation Laws. (arXiv:2102.11370v2 [quant-ph] UPDATED)

2021年3月26日 星期五 下午4:23 | | | Edward J. Gillis | | | quant-ph updates on arXiv.org |

Interactions establish correlations between physical systems. The correlations that persist through subsequent interactions with other physical systems pick out a distinct basis of decoherent branches of the wave function. This preferred basis is seen by many as the key to understanding what happens in quantum measurements. However, there is still no generally accepted explanation of how one particular branch is selected with the right probability. One possible explanation is that the entangling interactions that constitute measurements and generate decoherence induce an actual collapse of the wave function. This hypothesis leads to a stochastic collapse equation that does not require the introduction of any new physical constants. The collapse operator is based on interaction potentials, with a variable timing parameter related to the rate at which individual interactions generate the branching process. The distance-dependent nature of the interactions leads to the approximate localization of systems. The equation is consistent with strict conservation of momentum and orbital angular momentum, and it is also consistent with energy conservation within the accuracy allowed by the limited forms of energy that can be described within nonrelativistic theory.

Universal Constants as Manifestations of Relativity. (arXiv:2103.13854v1 [physics.hist-ph])

2021年3月26日 星期五 下午4:23 | | | physics.hist-ph updates on arXiv.org |

Authors: A. A. Sheykin

We study the possible interpretation of the “universal constants” by the classification of J.~M.~L\’evy-Leblond. $\hbar$ and $c$ are the most common example of constants of this type. Using Fock’s principle of the relativity w.r.t. observation means, we show that both $c$ and $\hbar$ can be viewed as manifestations of certain relativity. We also show that there is a possibility to interpret the Boltzmann’s constant in a similar way, and make some comments about the relativistic interpretation of the constant spacetime curvature and gravitational constant $G$.

Standard Quantum Mechanics without observers. (arXiv:2008.04930v3 [quant-ph] UPDATED)

2021年3月26日 星期五 下午4:23 | | | physics.hist-ph updates on arXiv.org |

Authors: Ovidiu Cristinel Stoica

The Projection Postulate from Standard Quantum Mechanics relies fundamentally on measurements. But measurements implicitly suggest the existence of anthropocentric notions like measuring devices, which should rather emerge from the theory. This article proposes an alternative formulation of the Standard Quantum Mechanics, in which the Projection Postulate is replaced with a version in which measurements and observations are not assumed as fundamental. More precisely, the Wigner functions representing the quantum states on the phase space are required to be tightly constrained to regions of the classical coarse-graining of the phase space. This ensures that states are quasiclassical at the macro level. Within a coarse-graining region, the time evolution of the Wigner functions representing the quantum system is required to obey the Liouville-von Neumann equation, the phase-space equivalent of the Schr\”odinger equation. The projection is postulated to happen when the system transitions from a coarse-graining region to others, by selecting one of them according to the Born rule, but without reference to a measurements. The connection with the standard formulation of Quantum Mechanics is explained, as well as the problems that the present formulation solves, in particular the Wigner’s friend type of paradoxes. Experimental consequences and open problems of the proposed formulation are discussed.

2021年3月26日 星期五 下午4:23 | | | 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 24 March 2021

**Source:** Physics Reports

Author(s): Alexander E. Hramov, Vladimir A. Maksimenko, Alexander N. Pisarchik

Conformal gravity does not predict flat galaxy rotation curves. (arXiv:2103.13451v1 [gr-qc])

2021年3月26日 星期五 下午4:23 | | | gr-qc updates on arXiv.org |

Authors: Michael Hobson, Anthony Lasenby

We reconsider the widely held view that the Mannheim–Kazanas (MK) vacuum solution for a static, spherically-symmetric system in conformal gravity (CG) predicts flat rotation curves, such as those observed in galaxies, without the need for dark matter. The conformal equivalence of the MK and Schwarzschild–de-Sitter (SdS) metrics, where the latter does not predict flat rotation curves, raises concerns that the prediction in the MK frame may be a gauge artefact. This ambiguity arises from assuming that, in each frame, test particles have fixed rest mass and follow timelike geodesics, which are not conformally invariant. The mass of such particles must instead be generated dynamically through interaction with a scalar field, the energy-momentum of which means that the spacetime outside a static, spherically-symmetric matter distribution in CG is, in general, not given by the MK vacuum solution. A unique solution does exist, however, for which the scalar field energy-momentum vanishes and the metric retains the MK form. Nonetheless, we show that in both the Einstein and MK frames of this solution, in which the scalar field is constant or radially-dependent, respectively, massive particles follow timelike geodesics of the SdS metric, thereby resolving the apparent frame dependence of physical predictions and unambiguously yielding rotation curves with no flat region. We further find that the general form of the conformal transformation linking the Einstein and MK frames is unique in preserving the structure of any diagonal static, spherically-symmetric metric with a radial coefficient that is (minus) the reciprocal of its temporal one. We also comment briefly on how our analysis resolves the long-standing uncertainty regarding gravitational lensing in the MK metric. (Abridged)

2021年3月26日 星期五 下午4:23 | | | gr-qc updates on arXiv.org |

Authors: Fabrizio Tamburini, Fabiano Feleppa, Bo Thidé

We test the validity of the Generalized Heisenberg’s Uncertainty principle in the presence of strong gravitational fields nearby rotating black holes; Heisenberg’s principle is supposed to require additional correction terms when gravity is taken into account, leading to a more general formulation also known as the Generalized Uncertainty Principle. Using as probe electromagnetic waves acquiring orbital angular momentum when lensed by a rotating black hole, we find from numerical simulations a relationship between the spectrum of the orbital angular momentum of light and the corrections needed to formulate the Generalized Uncertainty Principle, here characterized by the rescaled parameter $\beta_0$, a function of the Planck’s mass and the bare mass of the black hole. Then, from the analysis of the observed twisted light due to the gravitational field of the compact object observed in M87*, we find new limits for the parameter $\beta_0$. With this method, complementary to black hole shadow circularity analyses, we obtain more precise limits from the experimental data of M87*, confirming the validity of scenarios compatible with General Relativity, within the uncertainties due to the experimental errors present in EHT data and those due to the numerical simulations and analysis.

M-theory and the birth of the Universe. (arXiv:2102.11202v4 [hep-th] UPDATED)

2021年3月26日 星期五 下午4:23 | | | gr-qc updates on arXiv.org |

Authors: F.R. Klinkhamer

In this review article, we first discuss a possible regularization of the big bang curvature singularity of the standard Friedmann cosmology, where the curvature singularity is replaced by a spacetime defect. We then consider the hypothesis that a new physics phase gave rise to this particular spacetime defect. Specifically, we set out on an explorative calculation using the IIB matrix model, which has been proposed as a particular formulation of nonperturbative superstring theory (M-theory).

2021年3月26日 星期五 下午3:24 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Pezzulo, Giovanni and Sims, Matthew (2021) Modelling Ourselves: what the Free Energy Principle reveals about our implicit notions of representation. [Preprint]

A Refined Propensity Account for GRW Theory

2021年3月25日 星期四 下午3:37 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Lorenzetti, Lorenzo (2021) A Refined Propensity Account for GRW Theory. [Preprint]

Rigour and Thought Experiments: Burgess and Norton

2021年3月25日 星期四 下午3:36 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Brown, James Robert (2021) Rigour and Thought Experiments: Burgess and Norton. [Preprint]

“Can machines think?” The missing history of the Turing test

2021年3月25日 星期四 上午10:42 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Gonçalves, Bernardo (2021) “Can machines think?” The missing history of the Turing test. [Preprint]

Causal asymmetry from the perspective of a causal agent

2021年3月24日 星期三 下午3:04 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Evans, Peter W. and Milburn, Gerard J. and Shrapnel, Sally (2021) Causal asymmetry from the perspective of a causal agent. [Preprint]

The Value of Surprise in Science

2021年3月24日 星期三 下午3:00 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

French, Steven and Murphy, Alice (2021) The Value of Surprise in Science. [Preprint]

2021年3月22日 星期一 下午2:22 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Okon, Elias (2021) Defending Quantum Objectivity. [Preprint]

Against the Tyranny of ‘Pure States’ in Quantum Theory

2021年3月22日 星期一 下午2:20 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

de Ronde, Christian and Massri, Cesar (2019) Against the Tyranny of ‘Pure States’ in Quantum Theory. Foundations of Science. ISSN 1233-1821

**arXiv:2103.03743** (physics)[Submitted on 18 Jan 2021]

Nonnoetherian Lorentzian manifolds

A nonnoetherian spacetime is a Lorentzian manifold that contains a set of causal curves with no distinct interior points, called ‘pointal curves’. This new geometry recently arose in the study of nonnoetherian coordinate rings in algebraic geometry. We investigate properties of metrics on nonnoetherian spacetimes, and use the Hodge star operator to show that free dust particles have spin 12. We also reproduce the Kochen-Specker ψ-epistemic model of spin using the nonnoetherian metric, and show similarities between our model and spin entanglement for Bell states and four-photon entanglement swapping. Finally, we determine the stress-energy tensor of dust on such spacetimes, and find that it is only nonzero at points where dust is created or annihilated.

]]>上午9:59 | | | Blake C. Stacey | | | quant-ph updates on arXiv.org |

I comment briefly on derivations of the Born rule presented by Masanes et al. and by Hossenfelder.

Experimental SWAP test of infinite dimensional quantum states. (arXiv:2103.10219v1 [quant-ph])

上午9:59 | | | Chi-Huan Nguyen, Ko-Wei Tseng, Gleb Maslennikov, H. C. J. Gan, Dzmitry Matsukevich | | | quant-ph updates on arXiv.org |

Efficient overlap estimation of high-dimensional quantum states is an important task in quantum information and a core element in computational speedups of quantum machine learning. Here we experimentally demonstrate the SWAP test that measures the overlap of two motional states in a system of trapped $^{171}\mathrm{Yb}^+$ ions. To illustrate the versatility of our implementation, we report the overlap measurement of a variety of quantum states: Fock states, coherent states, squeezed vacuum states, and cat states. We highlight applications of the SWAP test by measuring the purity of mixed states. Our results enable quantum information processing with high dimensional quantum states.

上午9:59 | | | J. C. Pearl, E. G. Cavalcanti | | | quant-ph updates on arXiv.org |

In a recent work, it was shown by one of us (EGC) that Bell-Kochen-Specker inequality violations in phenomena satisfying the no-disturbance condition (a generalisation of the no-signalling condition) cannot in general be explained with a faithful classical causal model — that is, a classical causal model that satisfies the assumption of no fine-tuning. The proof of that claim however was restricted to Bell scenarios involving 2 parties or Kochen-Specker-contextuality scenarios involving 2 measurements per context. Here we show that the result holds in the general case of arbitrary numbers of parties or measurements per context; it is not an artefact of the simplest scenarios. This result unifies, in full generality, Bell nonlocality and Kochen-Specker contextuality as violations of a fundamental principle of classical causality. We identify, however, an implicit assumption in the former proof, making it explicit here: that certain operational symmetries of the phenomenon are reflected in the model, rather than requiring fine-tuned choices of model parameters. This clarifies a subtle but important distinction between Bell nonlocality and Kochen-Specker contextuality.

上午9:58 | | | physics.hist-ph updates on arXiv.org |

Authors: Ovidiu Cristinel Stoica

Is it possible that only the state vector exists, and the 3D-space, a preferred basis, a preferred factorization of the Hilbert space, and everything else, emerge uniquely from the Hamiltonian and the state vector?

In this article no-go theorems are given, showing that whenever such a candidate preferred structure exists and can distinguish among physically distinct states, infinitely many physically distinct structures of the same kind exist. The idea of the proof is very simple: it is always possible to make a unitary transformation of the candidate structure into another one of the same kind, but with respect to which the state of the system at a given time appears identical to its (physically distinct) state at any other time, or even to states from “alternative realities”.

Therefore, such minimalist approaches lead to strange consequences like “passive” travel in time and in alternative realities, realized simply by passive transformations of the Hilbert space.

These theorems affect all minimalist theories in which the only fundamental structures are the state vector and the Hamiltonian, whether they assume branching or state vector reduction, in particular, the version of Everett’s Interpretation coined by Carroll and Singh “Mad-dog Everettianism”, various proposals based on decoherence, proposals that aim to describe everything by the quantum structure, and proposals that spacetime emerges from a purely quantum theory of gravity.

The Stable Marriage Problem: An interdisciplinary review from the physicist’s perspective

上午9:58 | | | 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 16 March 2021

**Source:** Physics Reports

Author(s): Enrico Maria Fenoaltea, Izat B. Baybusinov, Jianyang Zhao, Lei Zhou, Yi-Cheng Zhang

Schr\”odinger’s cat for de Sitter spacetime. (arXiv:2012.10025v2 [gr-qc] UPDATED)

上午9:58 | | | gr-qc updates on arXiv.org |

Authors: Joshua Foo, Robert B. Mann, Magdalena Zych

Quantum gravity is expected to contain descriptions of semiclassical spacetime geometries in quantum superpositions. To date, no framework for modelling such superpositions has been devised. Here, we provide a new phenomenological description for the response of quantum probes (i.e. Unruh-deWitt detectors) on a spacetime manifold in quantum superposition. By introducing an additional control degree of freedom, one can assign a Hilbert space to the spacetime, allowing it to exist in a superposition of spatial or curvature states. Applying this approach to static de Sitter space, we discover scenarios in which the effects produced by the quantum spacetime are operationally indistinguishable from those induced by superpositions of Rindler trajectories in Minkowski spacetime. The distinguishability of such quantum spacetimes from superpositions of trajectories in flat space reduces to the equivalence or non-equivalence of the field correlations between the superposed amplitudes.

Typicality of Dynamics and Laws of Nature

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

Filomeno, Aldo (2021) Typicality of Dynamics and Laws of Nature. [Preprint]

The Philosophy of Quantum Computing

2021年3月17日 星期三 上午10:56 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Cuffaro, Michael E. (2021) The Philosophy of Quantum Computing. [Preprint]

Does the No Alternatives Argument need Gerrymandering to Be Significant?

2021年3月17日 星期三 上午10:51 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Dawid, Richard (2021) Does the No Alternatives Argument need Gerrymandering to Be Significant? [Preprint]

Four Postulates of Quantum Mechanics Are Three

2021年3月16日 星期二 下午6:00 | | | Gabriele Carcassi, Lorenzo Maccone, and Christine A. Aidala | | | PRL: General Physics: Statistical and Quantum Mechanics, Quantum Information, etc. |

Author(s): Gabriele Carcassi, Lorenzo Maccone, and Christine A. Aidala

The tensor product postulate of quantum mechanics states that the Hilbert space of a composite system is the tensor product of the components’ Hilbert spaces. All current formalizations of quantum mechanics that do not contain this postulate contain some equivalent postulate or assumption (sometimes…

[Phys. Rev. Lett. 126, 110402] Published Tue Mar 16, 2021

Gauge-underdetermination and shades of locality in the Aharonov-Bohm effect

2021年3月15日 星期一 下午4:20 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Mulder, Ruward A. (2021) Gauge-underdetermination and shades of locality in the Aharonov-Bohm effect. [Preprint]

]]>下午1:11 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Wallace, David (2019) Observability, redundancy and modality for dynamical symmetry transformations. [Preprint]

下午1:09 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Gryb, Sean and Sloan, David (2021) When scale is surplus. [Preprint]

Sonne und Mond, or, the good, the bad, and the ugly: comments on the debate between MOND and ΛCDM

下午1:08 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Helbig, Phillip (2021) Sonne und Mond, or, the good, the bad, and the ugly: comments on the debate between MOND and ΛCDM. The Observatory, 140 (1279). pp. 225-247. ISSN 0029-7704

From Unobservable to Observable: Entity Change and Scientific Realism

下午1:05 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Allzén, Simon (2021) From Unobservable to Observable: Entity Change and Scientific Realism. [Preprint]

Wigner’s friend and the quasi-ideal clock. (arXiv:2009.10218v2 [quant-ph] UPDATED)

2021年3月12日 星期五 下午4:44 | | | Vinicius P. Rossi, Diogo O. Soares-Pinto | | | quant-ph updates on arXiv.org |

In 1962, Eugene P. Wigner introduced a thought experiment that highlighted the incompatibility in quantum theory between unitary evolution and wave function reduction in a measurement. This work resulted in a class of thought experiments often called Wigner’s Friend Scenarios, which have been providing insights over many frameworks and interpretations of quantum theory. Recently, a no-go theorem obtained by Daniela Frauchiger and Renato Renner brought attention back to the Wigner’s Friend and its potential of putting theories to test. Many answers to this result pointed out how timing in the thought experiment could be yielding a paradox. In this work, we ask what would happen if the isolated friend in a Wigner’s Friend Scenario did not share a time reference frame with the outer observer, and time should be tracked by a quantum clock. For this purpose, we recollect concepts provided by the theory of quantum reference frames and the quantum resource theory of asymmetry, to learn how to internalize time in this scenario, and introduce a model for a feasible quantum clock proposed by Mischa P. Woods, Ralph Silva and Jonathan Oppenheim, called the quasi-ideal clock. Our results have shown that no decoherent behavior comes from this approach, and the disagreement between the superobserver and its friend persists even for an imprecise clock on Wigner’s side. However, the gaussian spread of this clock model can control what observables do not raise a paradox, indicating the relevance of deepening this analysis.

Phase Space Logic. (arXiv:2102.06572v2 [quant-ph] UPDATED)

2021年3月12日 星期五 下午4:44 | | | Niklas Johansson, Felix Huber, Jan-Åke Larsson | | | quant-ph updates on arXiv.org |

We propose a phase space logic that can capture the behavior of quantum and quantum-like systems. The proposal is similar to the more generic concept of epistemic logic: it encodes knowledge or perhaps more correctly, predictions about outcomes of future observations on some systems. For a quantum system, these predictions are statements about future outcomes of measurements performed on specific degrees of freedom of the system. The proposed logic will include propositions and their relations including connectives, but importantly also transformations between propositions on different degrees of freedom of the systems. A key point is the addition of a transformation that allows to convert propositions about single systems into propositions about correlations between systems. We will see that subtle choices of the properties of the transformations lead to drastically different underlying mathematical models; one choice gives stabilizer quantum mechanics, while another choice gives Spekkens’ toy theory. This points to a crucial basic property of quantum and quantum-like systems that can be handled within the present phase space logic by adjusting the mentioned choice. It also enables a discussion on what behaviors are properly quantum or only quantum-like, relating to that choice and how it manifests in the system under scrutiny.

Positivity Bounds on Dark Energy: When Matter Matters. (arXiv:2103.06855v1 [astro-ph.CO])

2021年3月12日 星期五 下午4:44 | | | gr-qc updates on arXiv.org |

Authors: Claudia de Rham, Scott Melville, Johannes Noller

Positivity bounds – constraints on any low-energy effective field theory imposed by the fundamental axioms of unitarity, causality and locality in the UV – have recently been used to constrain scalar-tensor theories of dark energy. However, the coupling to matter fields has so far played a limited role. We show that demanding positivity when including interactions with standard matter fields leads to further constraints on the dark energy parameter space. We demonstrate how implementing these bounds as theoretical priors affects cosmological parameter constraints and explicitly illustrate the impact on a specific Effective Field Theory for dark energy. We also show in this model that the existence of a standard UV completion requires that gravitational waves must travel superluminally on cosmological backgrounds.

Wave optics of quantum gravity for light and particles. (arXiv:2012.02288v2 [gr-qc] UPDATED)

2021年3月12日 星期五 下午4:44 | | | gr-qc updates on arXiv.org |

Authors: S.L. Cherkas, V.L. Kalashnikov

Effects of the quantum gravity under Minkowsky space-time background are considered. It is shown that despite the absence of the full theory of quantum gravity, very concrete and definite predictions could be made for the influence of the quantum gravitational fluctuations on the propagation of the particles and light. It is shown that the operator of the gravitational potential in a vacuum has the correlator $<0|\hat \Phi({\bf r})\hat \Phi({\bf r}^\prime)|0>\sim \delta({\bf r}-{\bf r}^\prime)/M_p^3$. As a result, nonrelativistic massive particle waves lose their coherence at a distance proportional to the fourth degree of the particle velocity. Coherent electromagnetic wave attenuates due to metric fluctuations inversely proportionally to the fifth degree of a frequency.

The Spacetime Picture in Quantum Gravity. (arXiv:2012.03994v3 [gr-qc] UPDATED)

2021年3月12日 星期五 下午4:44 | | | gr-qc updates on arXiv.org |

Authors: Alejandro Ascárate

We propose an approach which, by combining insights from Loop Quantum Gravity (LQG), Topos theory, Non-commutative Geometry \`a la Connes, and spacetime relationalism, provides fertile ground for the search of an adequate spacetime picture in Quantum Gravity. With this approach, we obtain a novel way of deducing the quantization of the possible values for the area of a surface. One gets the same area values than those from the area operator in standard LQG, but our approach makes a further prediction: some smaller values and sub-divisions are also allowed. In addition, the area arises as a noncommutative distance between two noncommutative points, and thus they should be interpreted as irreducible string-like objects at the physical level (where the area interpretation for the noncommutative distance holds).

2021年3月12日 星期五 下午4:44 | | | gr-qc updates on arXiv.org |

Authors: I.M. Burbano, T. Rick Perche, Bruno de S. L. Torres

Particle detectors are an ubiquitous tool for probing quantum fields in the context of relativistic quantum information (RQI). We formulate the Unruh-DeWitt (UDW) particle detector model in terms of the path integral formalism. The formulation is able to recover the results of the model in general globally hyperbolic spacetimes and for arbitrary detector trajectories. Integrating out the detector’s degrees of freedom yields a line defect that allows one to express the transition probability in terms of Feynman diagrams. Inspired by the light-matter interaction, we propose a gauge invariant detector model whose associated line defect is related to the derivative of a Wilson line. This is another instance where nonlocal operators in gauge theories can be interpreted as physical probes for quantum fields.

A puzzle about laws and explanation

2021年3月12日 星期五 上午8:00 | | | Latest Results for Synthese |

**Abstract**

In this paper, we argue that the popular claim that laws of nature explain their instances (*explanatory laws*) creates a philosophical puzzle when it is combined with the widely held requirement that explanations need to be underpinned by ‘wordly’ relations (*explanatory realism*). We argue that a “direct solution” to the puzzle that accounts for both *explanatory laws* and *explanatory realism* requires endorsing at least a radical metaphysics. Then, we examine the ramifications of a “skeptical solution”, i.e., dissolving it by giving up at least one of these two claims, and argue that adopting it is more favorable to Humean reductionists than to anti-reductionists about laws of nature.

Weak Measurement of a Superconducting Qubit Reconciles Incompatible Operators

2021年3月11日 星期四 下午6:00 | | | Jonathan T. Monroe, Nicole Yunger Halpern, Taeho Lee, and Kater W. Murch | | | PRL: General Physics: Statistical and Quantum Mechanics, Quantum Information, etc. |

Author(s): Jonathan T. Monroe, Nicole Yunger Halpern, Taeho Lee, and Kater W. Murch

Traditional uncertainty relations dictate a minimal amount of noise in incompatible projective quantum measurements. However, not all measurements are projective. Weak measurements are minimally invasive methods for obtaining partial state information without projection. Recently, weak measurements …

[Phys. Rev. Lett. 126, 100403] Published Thu Mar 11, 2021

Typicality in the Foundations of Statistical Physics and Born’s Rule

2021年3月10日 星期三 下午4:05 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Duerr, Detlef and Struyve, Ward (2020) Typicality in the Foundations of Statistical Physics and Born’s Rule. pp. 35-44.

The visibility of philosophy of science in the sciences, 1980–2018

2021年3月10日 星期三 下午4:01 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Khelfaoui, Mahdi and Gingras, Yves and Lemoine, Maël and Pradeu, Thomas (2021) The visibility of philosophy of science in the sciences, 1980–2018. Synthese. ISSN 0039-7857

2021年3月8日 星期一 下午6:00 | | | Isabelle Jianing Geng, Kimberly Golubeva, and Gilad Gour | | | PRL: General Physics: Statistical and Quantum Mechanics, Quantum Information, etc. |

Author(s): Isabelle Jianing Geng, Kimberly Golubeva, and Gilad Gour

Symmetric informationally complete (SIC) positive operator valued measures (POVMs) are a class of quantum measurements which, in addition to being informationally complete, satisfy three conditions: (1) every POVM element is rank one, (2) the Hilbert-Schmidt inner product between any two distinct el…

[Phys. Rev. Lett. 126, 100401] Published Mon Mar 08, 2021

A Brief Historical Perspective on the Consistent Histories Interpretation of Quantum Mechanics

2021年3月7日 星期日 上午6:04 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Rocha, Gustavo and Rickels, Dean and Boge, Florian J. (2021) A Brief Historical Perspective on the Consistent Histories Interpretation of Quantum Mechanics. [Preprint]

When randomness is intrinsic, formalize it

2021年3月7日 星期日 上午6:02 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

De Peuter, Steven (2021) When randomness is intrinsic, formalize it. [Preprint]

]]>下午1:51 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Skokowski, Paul (2021) Observing a Superposition. [Preprint]

上午10:29 | | | Máté Farkas, Maria Balanzó-Juandó, Karol Łukanowski, Jan Kołodyński, Antonio Acín | | | quant-ph updates on arXiv.org |

Device-independent quantum key distribution is a secure quantum cryptographic paradigm that allows two honest users to establish a secret key, while putting minimal trust in their devices. Most of the existing protocols have the following structure: first, a bipartite nonlocal quantum state is distributed between the honest users, who perform local projective measurements to establish nonlocal correlations. Then, they announce the implemented measurements and extract a secure key by post-processing their measurement outcomes. We show that no protocol of this form allows for establishing a secret key when implemented on certain entangled nonlocal states, namely on a range of entangled two-qubit Werner states. To prove this result, we introduce a technique for upper-bounding the asymptotic key rate of device-independent quantum key distribution protocols, based on a simple eavesdropping attack. Our results imply that either different tools — such as different reconciliation techniques or non-projective measurements — are needed for device-independent quantum key distribution in the large-noise regime, or Bell nonlocality is not sufficient for this task.

Bell-Fine theorems on complementarity. (arXiv:2103.03101v1 [quant-ph])

上午10:29 | | | Elisa Masa, Laura Ares, Alfredo Luis | | | quant-ph updates on arXiv.org |

We provide a Bell-type analysis of complementarity via a suitably designed hidden-variables model that leads to a set of Bell-like inequalities that can be tested by easily measured observables. We show that this violation is equivalent to Fine-like theorems regarding the lack of a joint distribution for incompatible observables. This is illustrated by path-interference duality in a Young interferometer.

A non local phase field model of Bohm’s quantum potential. (arXiv:2103.03162v1 [quant-ph])

上午10:29 | | | Roberto Mauri | | | quant-ph updates on arXiv.org |

Assuming that the free energy of a gas depends non-locally on the logarithm of its mass density, the body force in the resulting equation of motion consists of the sum of density gradient terms. Truncating this series after the second term, Bohm’s quantum potential and the Madelung equation are identically obtained, showing explicitly that some of the hypotheses that led to the formulation of quantum mechanics admit a classical interpretation based on non-locality.

上午10:29 | | | Giuseppe Castagnoli | | | quant-ph updates on arXiv.org |

It can be argued that the ordinary description of the reversible quantum process between two one-to-one correlated measurement outcomes is incomplete because, by not specifying the direction of causality, it allows causal structures that violate the time symmetry that is required of a reversible process. This also means that it can be completed simply by time-symmetrizing it, namely by requiring that the initial and final measurements evenly contribute to the selection of their correlated pair of outcomes. This leaves the description unaltered but shows that it is the quantum superposition of unobservable time-symmetrized instances whose causal structure is completely defined. Each instance consists of a causal loop: the final measurement that changes backwards in time the input state of the unitary transformation that leads to the state immediately before it. In former works, we have shown that such loops exactly explain the quantum computational speedup and quantum nonlocality. In this work we show that they lead to a completion of the anthropic principle that allows a universe evolution with quantum speedup.

上午10:29 | | | physics.hist-ph updates on arXiv.org |

Authors: Ruward A. Mulder

I address the view that the classical electromagnetic potentials are shown by the Aharonov-Bohm effect to be physically real (which I dub: ‘the potentials view’). I give a historico-philosophical presentation of this view and assess its prospects, more precisely than has so far been done in the literature. Taking the potential as physically real runs prima facie into ‘gauge-underdetermination’: different gauge choices represent different physical states of affairs and hence different theories. I then illustrate this theme by what I take to be the basic insight of the AB effect for the potentials view, namely that the gauge equivalence class that directly corresponds to the electric and magnetic fields (which I call the Wide Equivalence Class) is too wide, i.e., the Narrow Equivalence Class encodes additional physical degrees of freedom: these only play a distinct role in a multiply-connected space. There is a trade-off between explanatory power and gauge symmetries. Although this narrower equivalence class gives a explanation in terms of `local interactions’, locality is not satisfied in the sense of signal locality. It is therefore intellectually mandatory to seek desiderata that will distinguish even within these narrower equivalence classes, i.e. will prefer some elements of such an equivalence class over others. I consider various formulations of locality, such as Bell locality, local interaction Hamiltonians, and signal locality. I show that Bell locality can only be evaluated if one fixes the gauge freedom completely. Yet, an explanation in terms of signal locality can be accommodated by the Lorenz gauge: the potentials propagate in waves at finite speed. I therefore suggest the Lorenz gauge potentials theory — an even narrower gauge equivalence relation — as the ontology of electrodynamics.

上午10:29 | | | physics.hist-ph updates on arXiv.org |

Authors: Galina Weinstein

This paper comprehensively explores Stephen Hawking’s interaction with Jacob Bekenstein. Both Hawking and Bekenstein benefited from the interaction with each other. It is shown that Hawking’s interaction with Bekenstein drove him to solve the problems in Bekenstein’s black hole thermodynamics in terms of a new thermal radiation mechanism. Hawking derived the thermal radiation using a semiclassical approximation in which the matter fields are treated quantum mechanically on a classical spacetime background. Hawking’s semiclassical approximation yielded a simple formula for the entropy of the black hole, which turned out to be equivalent to Bekenstein’s equation for entropy.

上午10:29 | | | gr-qc updates on arXiv.org |

Authors: João C. Lobato, Isabela S. Matos, Lucas T. Santana, Ribamar R. R. Reis, Maurício O. Calvão

We explore different facets of the action of linearized gravitational waves in Minkowski spacetime background upon light, under the electromagnetic geometrical optics limit, covering the main aspects: light trajectory perturbations, radar distance and light frequency shift. For this purpose, we consider observers comoving with the transverse traceless gauge coordinates. We compute the parametrized null geodesics exchanged between two of these observers, presenting explicitly the constants of motion as functions of observables, determining therefrom both the radar distance between the observers and the electromagnetic round-trip frequency shift caused by the gravitational wave. Also, a comparison is made between these results and what one would obtain by using a frequently adopted hybrid model in which the spatial trajectory of light is unchanged. Finally, we revisit and provide an explanation, resorting to the constancy of the phase along a light ray, to the fundamental puzzling question of how one is able to detect gravitational waves by means of interferometry if both light wavelength and detector arms are stretched.

上午10:29 | | | gr-qc updates on arXiv.org |

Authors: João C. Lobato, Isabela S. Matos, Lucas T. Santana, Ribamar R. R. Reis, Maurício O. Calvão

In this second article of the series, we apply our recently derived equation for the electric field propagation along light rays [arXiv:2004.03496], valid on the electromagnetic geometrical optics limit, to the special case of a toy interferometer used to detect gravitational waves in a flat background. Such an equation shows that, assuming the detector is in the transverse-traceless frame, which has a local shearing relative motion due to the gravitational wave perturbations, the electric field does not propagate as in an inertial reference frame in Minkowski spacetime. We present the electric field at the end of the interferometric process, for arbitrary arm configurations with respect to the plane gravitational wave packet propagation direction. Then, for normal incidence, we compute the interference pattern and, in addition to the usual term associated with the difference in path traveled by light in the arms, we deduce two new contributions to the final intensity, arising from: (i) the round-trip electromagnetic frequency shift and (ii) the divergence of the light beam. Their quantitative relevance is compared to the traditional contribution and shown to be typically negligible due to the geometrical optics regime of light. Moreover, a non-parallel transport of the polarization vector takes place, in general, because of the gravitational wave, a feature which could generate further contributions. However, we conclude that for the normal incidence case such vector is parallel transported, preventing this kind of correction.

How does the Planck scale affect qubits?. (arXiv:2103.03093v1 [quant-ph])

上午10:29 | | | gr-qc updates on arXiv.org |

Authors: Matthew J. Lake

Gedanken experiments in quantum gravity motivate generalised uncertainty relations (GURs) implying deviations from the standard quantum statistics close to the Planck scale. These deviations have been extensively investigated for the non-spin part of the wave function but existing models tacitly assume that spin states remain unaffected by the quantisation of the background in which the quantum matter propagates. Here, we explore a new model of nonlocal geometry in which the Planck-scale smearing of classical points generates GURs for angular momentum. These, in turn, imply an analogous generalisation of the spin uncertainty relations. The new relations correspond to a novel representation of {\rm SU(2)} that acts nontrivially on both subspaces of the composite state describing matter-geometry interactions. For single particles each spin matrix has four independent eigenvectors, corresponding to two $2$-fold degenerate eigenvalues $\pm (\hbar + \beta)/2$, where $\beta$ is a small correction to the effective Planck’s constant. These represent the spin states of a quantum particle immersed in a quantum background geometry and the correction by $\beta$ emerges as a direct result of the interaction terms. In addition to the canonical qubits states, $\ket{0} = \ket{\uparrow}$ and $\ket{1} = \ket{\downarrow}$, there exist two new eigenstates in which the spin of the particle becomes entangled with the spin sector of the fluctuating spacetime. We explore ways to empirically distinguish the resulting `geometric’ qubits, $\ket{0′}$ and $\ket{1′}$, from their canonical counterparts.

Interpreting Mass via Riemannian Polyhedra. (arXiv:2103.03201v1 [math.DG])

上午10:29 | | | gr-qc updates on arXiv.org |

Authors: Pengzi Miao

We give an account of some recent development that connects the concept of mass in general relativity to the geometry of large Riemannian polyhedra, in the setting of both asymptotically flat and asymptotically hyperbolic manifolds.

上午10:29 | | | gr-qc updates on arXiv.org |

Authors: Kyu-Hyun Chae, Federico Lelli, Harry Desmond, Stacy S. McGaugh, Pengfei Li, James M. Schombert

The strong equivalence principle (SEP) distinguishes General Relativity from other viable theories of gravity. The SEP demands that the internal dynamics of a self-gravitating system under free-fall in an external gravitational field should not depend on the external field strength. We test the SEP by investigating the external field effect (EFE) in Milgromian dynamics (MOND), proposed as an alternative to dark matter in interpreting galactic kinematics. We report a detection of this EFE using galaxies from the Spitzer Photometry and Accurate Rotation Curves (SPARC) sample together with estimates of the large-scale external gravitational field from an all-sky galaxy catalog. Our detection is threefold: (1) the EFE is individually detected at $8\sigma$ to $11\sigma$ in “golden” galaxies subjected to exceptionally strong external fields, while it is not detected in exceptionally isolated galaxies, (2) the EFE is statistically detected at more than $4\sigma$ from a blind test of 153 SPARC rotating galaxies, giving a mean value of the external field consistent with an independent estimate from the galaxies’ environments, and (3) we detect a systematic downward trend in the weak gravity part of the radial acceleration relation at the right acceleration predicted by the EFE of the MOND modified gravity. Tidal effects from neighboring galaxies in the $\Lambda$CDM context are not strong enough to explain these phenomena. They are not predicted by existing $\Lambda$CDM models of galaxy formation and evolution, adding a new small-scale challenge to the $\Lambda$CDM paradigm. Our results point to a breakdown of the SEP, supporting modified gravity theories beyond General Relativity.

上午10:29 | | | gr-qc updates on arXiv.org |

Authors: T. Rick Perche, Jonas Neuser

We reduce Dirac’s spinor formalism for a spin 1/2 particle to a complex wavefunction description in curved spacetimes. We consider a localized fermionic particle in curved spacetimes and perform an expansion in terms of the acceleration and curvature around the center of mass of the system, generalizing the results of [Phys. Rev. D 22, 1922]. Under a non-relativistic approximation, one obtains a quantum description in a Hilbert space of complex wavefunctions defined in the rest space of the system. The wavefunction of the particle then evolves according to a modified Schr\”odinger equation associated with a symmetric Hamiltonian. When compared to the standard Schr\”odinger equation for a wavefunction, we obtain corrections in terms of the acceleration of the system’s center of mass and curvature of spacetime along its trajectory. In summary, we provide a formalism for the use of a complex wavefunction to describe a localized quantum particle in curved spacetimes.

Hidden Symmetry of Vanishing Love. (arXiv:2103.01234v2 [hep-th] UPDATED)

上午10:29 | | | gr-qc updates on arXiv.org |

Authors: Panagiotis Charalambous, Sergei Dubovsky, Mikhail M. Ivanov

We show that perturbations of massless fields in the Kerr black hole background enjoy a hidden infinite-dimensional (“Love”) symmetry in the properly defined near zone approximation. Love symmetry mixes IR and UV modes. Still, this approximate symmetry allows us to derive exact results about static tidal responses. Generators of the Love symmetry are globally well defined and have a smooth Schwarzschild limit. The Love symmetry contains an $SL(2,\mathbb{R})\times {U}(1)$ subalgebra. Generic regular solutions of the near zone Teukolsky equation form infinite-dimensional $SL(2,\mathbb{R})$ representations. In some special cases ($\hat{\ell}$ parameter is an integer), these are highest weight representations. This situation corresponds to vanishing Love numbers. In particular, static perturbations of four-dimensional Schwarzschild black holes belong to finite-dimensional representations. Other known facts about static Love numbers also acquire an elegant explanation in terms of the $SL(2,\mathbb{R})$ representation theory.

Polarization out of the vortex

2021年3月4日 星期四 上午8:00 | | | David J. Masiello | | | Nature Physics – Issue – nature.com science feeds |

Nature Physics, Published online: 04 March 2021; doi:10.1038/s41567-021-01167-6

The virtual photons that are exchanged when a free-electron vortex beam interacts with a nanoscopic target unlock an explicit connection between polarized optical spectroscopy and the inelastic scattering of scalar electron waves.

The Everett interpretation: structure

2021年3月3日 星期三 下午4:02 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Saunders, Simon (2021) The Everett interpretation: structure. [Preprint]

The many-worlds theory of consciousness

2021年3月3日 星期三 下午4:01 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

List, Christian (2021) The many-worlds theory of consciousness. [Preprint]

Curie’s Principle and Causal Graphs

2021年3月3日 星期三 下午3:57 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Kinney, David (2021) Curie’s Principle and Causal Graphs. [Preprint]

Radical interpretation and decision theory

2021年3月3日 星期三 上午8:00 | | | Latest Results for Synthese |

**Abstract**

This paper takes issue with an influential interpretationist argument for physicalism about intentionality based on the possibility of radical interpretation. The interpretationist defends the physicalist thesis that the intentional truths supervene on the physical truths by arguing that it is possible for a radical interpreter, who knows all of the physical truths, to work out the intentional truths about what an arbitrary agent believes, desires, and means without recourse to any further empirical information. One of the most compelling arguments for the possibility of radical interpretation, associated most closely with David Lewis and Donald Davidson, gives a central role to decision theoretic representation theorems, which demonstrate that if an agent’s preferences satisfy certain constraints, it is possible to deduce probability and utility functions that represent her beliefs and desires. We argue that an interpretationist who wants to rely on existing representation theorems in defence of the possibility of radical interpretation faces a trilemma, each horn of which is incompatible with the possibility of radical interpretation.

Dynamical Symmetries and Symmetry-Protected Selection Rules in Periodically Driven Quantum Systems

2021年3月2日 星期二 下午6:00 | | | Georg Engelhardt and Jianshu Cao | | | PRL: General Physics: Statistical and Quantum Mechanics, Quantum Information, etc. |

Author(s): Georg Engelhardt and Jianshu Cao

In recent experiments, the light-matter interaction has reached the ultrastrong coupling limit, which can give rise to dynamical generalizations of spatial symmetries in periodically driven systems. Here, we present a unified framework of dynamical-symmetry-protected selection rules based on Floquet…

[Phys. Rev. Lett. 126, 090601] Published Tue Mar 02, 2021

The Measurement Problem of Consciousness

2021年3月2日 星期二 上午8:59 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Browning, Heather and Veit, Walter (2021) The Measurement Problem of Consciousness. [Preprint]

Operational Resource Theory of Imaginarity

2021年3月1日 星期一 下午6:00 | | | Kang-Da Wu, Tulja Varun Kondra, Swapan Rana, Carlo Maria Scandolo, Guo-Yong Xiang, Chuan-Feng Li, Guang-Can Guo, and Alexander Streltsov | | | PRL: General Physics: Statistical and Quantum Mechanics, Quantum Information, etc. |

Author(s): Kang-Da Wu, Tulja Varun Kondra, Swapan Rana, Carlo Maria Scandolo, Guo-Yong Xiang, Chuan-Feng Li, Guang-Can Guo, and Alexander Streltsov

There exist real quantum states which can be perfectly distinguished via local operations and classical communication, but which cannot be distinguished with any nonzero probability if one of the parties has no access to imaginarity.

[Phys. Rev. Lett. 126, 090401] Published Mon Mar 01, 2021

A pragmatic approach to the ontology of models

2021年3月1日 星期一 下午4:57 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Antoniou, Antonis (2021) A pragmatic approach to the ontology of models. [Preprint]

Scientific Realism and Empirical Confirmation: a Puzzle

2021年3月1日 星期一 下午4:56 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Allzén, Simon (2021) Scientific Realism and Empirical Confirmation: a Puzzle. [Preprint]

Why We Should Be Suspicious of Conspiracy Theories. A Novel Demarcation Problem

2021年2月28日 星期日 上午7:40 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Boudry, Maarten (2020) Why We Should Be Suspicious of Conspiracy Theories. A Novel Demarcation Problem. [Preprint]

]]>The quantum measurement problem is the most fundamental question of all: How the ghostly quantum mechanical coexistence of many mutually incompatible possibilities result in the concrete reality of the normal world, even though we and our measuring instruments are all made of atoms obeying quantum mechanics. In this brief article we lay down the criteria for such a mechanism.

]]>上午10:17 | | | Daniel J. Lum, Michael D. Mazurek, Alexander Mikhaylov, Kristen M. Parzuchowski, Ryan N. Wilson, Ralph Jimenez, Thomas Gerrits, Martin J. Stevens, Marcus T. Cicerone, Charles H. Camp Jr | | | quant-ph updates on arXiv.org |

We demonstrate the preservation of time-energy entanglement of near-IR photons through thick biological media ($\leq$1.55 mm) and tissue ($\leq$ 235 $\mu$m) at room temperature. Using a Franson-type interferometer, we demonstrate interferometric contrast of over 0.9 in skim milk, 2% milk, and chicken tissue. This work supports the many proposed opportunities for nonclassical light in biological imaging and analyses from sub-shot noise measurements to entanglement-enhanced fluorescence imaging, clearly indicating that the entanglement characteristics of photons can be maintained even after propagation through thick, turbid biological samples.

Quantum Contextuality. (arXiv:2102.13036v1 [quant-ph])

上午10:17 | | | Costantino Budroni, Adán Cabello, Otfried Gühne, Matthias Kleinmann, Jan-Åke Larsson | | | quant-ph updates on arXiv.org |

A central result in the foundations of quantum mechanics is the Kochen-Specker theorem. In short, it states that quantum mechanics is in conflict with classical models in which the result of a measurement does not depend on which other compatible measurements are jointly performed. Here, compatible measurements are those that can be performed simultaneously or in any order without disturbance. This conflict is generically called quantum contextuality. In this article, we present an introduction to this subject and its current status. We review several proofs of the Kochen-Specker theorem and different notions of contextuality. We explain how to experimentally test some of these notions and discuss connections between contextuality and nonlocality or graph theory. Finally, we review some applications of contextuality in quantum information processing.

上午10:17 | | | Patryk Lipka-Bartosik, Paul Skrzypczyk | | | quant-ph updates on arXiv.org |

Quantum catalysis is a fascinating concept which demonstrates that certain transformations can only become possible when given access to a specific resource that has to be returned unaffected. It was first discovered in the context of entanglement theory and since then applied in a number of resource-theoretic frameworks, including quantum thermodynamics. Although in that case the necessary (and sometimes also sufficient) conditions on the existence of a catalyst are known, almost nothing is known about the precise form of the catalyst state required by the transformation. In particular, it is not clear whether it has to have some special properties or be finely tuned to the desired transformation. In this work we describe a surprising property of multi-copy states: we show that in resource theories governed by majorization all resourceful states are catalysts for all allowed transformations. In quantum thermodynamics this means that the so-called “second laws of thermodynamics” do not require a fine-tuned catalyst but rather any state, given sufficiently many copies, can serve as a useful catalyst. These analytic results are accompanied by several numerical investigations that indicate that neither a multi-copy form nor a very large dimension catalyst are required to activate most allowed transformations catalytically.

Direct measurements of neutrino mass

上午10:17 | | | 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 February 2021

**Source:** Physics Reports

Author(s): Joseph A. Formaggio, André Luiz C. de Gouvêa, R.G. Hamish Robertson

上午10:17 | | | gr-qc updates on arXiv.org |

Authors: Nelson Falcon

The peculiarities of the inverse square law of Newtonian gravity in standard Big Bang Cosmology are discussed. It is shown that the incorporation of an additive term to Newtonian gravitation, as the inverse Yukawa-like field, allows remove the incompatibility between the flatness of the Universe and the density of matter in the Friedmann equation, provides a new approach for dark energy, and enable theoretical deduce the Hubble-Lemaitre’s law. The source of this inverse Yukawa-like field is the ordinary baryonic matter and represents the large-scale contribution of gravity in accordance with the Mach’s principle. It’s heuristically build from a specular reflection of the Yukawa potential, in agreement with astronomical and laboratory observables, result null in the inner solar system, weakly attractive in ranges of interstellar distances, very attractive in distance ranges comparable to the clusters of galaxies and repulsive in cosmic scales. Its implications in the missing mass of Zwicky, Virial Theorem, Kepler’s Third Law in Globular Clusters, rotations curves of galaxies, gravitational redshift and the Jean’s mass are discussed. The inclusion of the inverse Yukawa-like field in Newtonian gravitation predicts a graviton mass of at least 10-64 kg and could be an alternative to the paradigm of non-baryonic dark matter concomitant with the observables of the Big Bang.

上午10:17 | | | gr-qc updates on arXiv.org |

Authors: Jie Jiang, Aofei Sang, Ming Zhang

Recently, it was argued in [Phys. Rev. Lett. {\bf126}, 031102 (2021)] that the WCCC can serve as a constraint to high-order effective field theories. However, we find there exists a key error in their approximate black hole solution. After correcting it, their calculation cannot show the ability of WCCC to constrain the gravitational theories.

上午10:17 | | | gr-qc updates on arXiv.org |

Authors: Robert Brandenberger (McGill University)

I review the “Trans-Planckian Censorship Conjecture” (TCC) and its implications for cosmology, in particular for the inflationary universe scenario. Whereas the inflationary scenario is tightly constrained by the TCC, alternative early universe scenarios are not restricted.

Thermodynamics of Gambling Demons

2021年2月26日 星期五 下午6:00 | | | Gonzalo Manzano, Diego Subero, Olivier Maillet, Rosario Fazio, Jukka P. Pekola, and Édgar Roldán | | | PRL: General Physics: Statistical and Quantum Mechanics, Quantum Information, etc. |

Author(s): Gonzalo Manzano, Diego Subero, Olivier Maillet, Rosario Fazio, Jukka P. Pekola, and Édgar Roldán

In a new version of Maxwell’s demon, the tiny being plays the role of a gambler who knows when to quit.

[Phys. Rev. Lett. 126, 080603] Published Fri Feb 26, 2021

2021年2月26日 星期五 下午4:18 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Cuffaro, Michael E. and Doyle, Emerson P. (2020) Essay Review of Tanya and Jeffrey Bub’s Totally Random: Why Nobody Understands Quantum Mechanics: A Serious Comic on Entanglement. [Preprint]

A pragmatic approach to the ontology of models

2021年2月26日 星期五 上午8:00 | | | Latest Results for Synthese |

**Abstract**

What are scientific models? Philosophers of science have been trying to answer this question during the last three decades by putting forward a number of different proposals. Some say that models are best understood as abstract Platonic objects or fictional entities akin to Sherlock Holmes, while others focus on their mathematical nature and see them as set theoretical structures. Although each account has its own strengths in offering various insights on the nature of models, several objections have been raised against these views which still remain unanswered, making the debate on the ontology of models seem unresolvable. The primary aim of this paper is to show that a large part of these difficulties stems from an inappropriate reading of the main question on the ontology of models as a purely metaphysical question. Building on Carnap, it is argued that the question of the ontology of scientific models is either (i) an internal theoretical question within an already accepted linguistic framework or (ii) an external practical question regarding the choice of the most appropriate form of language in order to describe and explain the practice of scientific modelling. The main implication of this view is that the question of the ontology of models becomes a means of probing other related questions regarding the overall practice of scientific modelling, such as questions on the capacity of models to provide knowledge and the relation of models with background theories.

Non-equilibrium quantum dynamics and formation of the Bose polaron

2021年2月25日 星期四 上午8:00 | | | Jan J. Arlt | | | Nature Physics – Issue – nature.com science feeds |

Nature Physics, Published online: 25 February 2021; doi:10.1038/s41567-021-01184-5

Quantum impurities immersed in a bosonic environment can evolve into polaronic quasiparticles, so-called polarons. Interferometric measurement reveals this transition, which involves three different regimes dominated by few-body and many-body dynamics.

I could do that in my sleep: skilled performance in dreams

2021年2月25日 星期四 上午8:00 | | | Latest Results for Synthese |

**Abstract**

The experience of skilled action occurs in dreams if we take dream reports at face value. However, what these reports indicate requires nuanced analysis. It is uncertain what it means to perform any action in a dream whatsoever. If skilled actions do occur in dreams, this has important implications for both theory of action and theory of dreaming. Here, it is argued that since some dreams generate a convincing, hallucinated world where we have virtual bodies that interact with virtual objects, there is a sense in which we can perform virtual actions. Further, we can also perform *skilfully,* although not all apparent skilful performance is as it seems. Since the dream world is generated by the dreamer’s own mind, it can be difficult to determine whether the dream world simply allows goals to be achieved without the abilities that would be required in a similar waking scenario. Because of this, individual dream reports alone are insufficient to determine what skills are demonstrated in a particular dream. However, taken with evidence from REM sleep behaviour disorder, incompetent dreams, lucid dreams and motor-skill practise, it is likely that skilled virtual dream performance at times involves both opportunity for virtual behaviour and the display of competence. Evidence from cognitive science suggests that dreamers can also lose competence through forgetting and other cognitive incapacities but, more surprisingly, it is possible to gain abilities in a robust sense, consistent with the idea that some dreams, at least, are virtual realities rather than imagination.

Grounding, Conceivability, and the Mind-Body Problem

2021年2月23日 星期二 上午11:41 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Khudairi, Hasen (2016) Grounding, Conceivability, and the Mind-Body Problem. Synthese. pp. 1-8. ISSN 0039-7857

Beyond Causal Explanation: Einstein’s Principle Not Reichenbach’s

2021年2月23日 星期二 上午11:29 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Silberstein, Michael and Stuckey, W. M. (2021) Beyond Causal Explanation: Einstein’s Principle Not Reichenbach’s. In: UNSPECIFIED.

Models of the Nucleus: Incompatible Things, Compatible Processes

2021年2月23日 星期二 上午11:26 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Penn, William (2021) Models of the Nucleus: Incompatible Things, Compatible Processes. [Preprint]

Probing Theoretical Statements with Thought Experiments

2021年2月23日 星期二 上午11:26 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

El Skaf, Rawad (2021) Probing Theoretical Statements with Thought Experiments. Synthese. ISSN 1573-0964

]]>上午7:49 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Fraser, Doreen (2021) Review of Mark Wilson, Physics Avoidance. [Preprint]

上午7:49 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Chen, Eddy Keming (2021) Fundamental Nomic Vagueness. [Preprint]

2021年2月20日 星期六 上午9:56 | | | physics.hist-ph updates on arXiv.org |

Authors: Wolfgang Bietenholz

A century ago Srinivasa Ramanujan – the great self-taught Indian genius of mathematics – died, shortly after returning from Cambridge, UK, where he had collaborated with Godfrey Hardy. Ramanujan contributed numerous outstanding results to different branches of mathematics, like analysis and number theory, with a focus on special functions and series. Here we refer to apparently weird values which he assigned to two simple divergent series, $\sum_{n \geq 1} n$ and $\sum_{n \geq 1} n^{3}$. These values are sensible, however, as analytic continuations, which correspond to Riemann’s $\zeta$-function. Moreover, they have applications in physics: we discuss the vacuum energy of the photon field, from which one can derive the Casimir force, which has been experimentally measured. We also discuss its interpretation, which remains controversial. This is a simple way to illustrate the concept of renormalization, which is vital in quantum field theory.

Agreement between observers: a physical principle?. (arXiv:2102.08966v1 [quant-ph])

2021年2月20日 星期六 上午9:56 | | | Patricia Contreras-Tejada, Giannicola Scarpa, Aleksander M. Kubicki, Adam Brandenburger, Pierfranceso La Mura | | | quant-ph updates on arXiv.org |

Is the world quantum? An active research line in quantum foundations is devoted to exploring what constraints can rule out the post-quantum theories that are consistent with experimentally observed results. We explore this question in the context of epistemics, and ask whether agreement between observers can serve as a physical principle that must hold for any theory of the world. Aumann’s seminal Agreement Theorem states that two (classical) agents cannot agree to disagree. We propose an extension of this theorem to no-signaling settings. In particular, we establish an Agreement Theorem for quantum agents, while we construct examples of (post-quantum) no-signaling boxes where agents can agree to disagree. The PR box is an extremal instance of this phenomenon. These results make it plausible that agreement between observers might be a physical principle, while they also establish links between the fields of epistemics and quantum information that seem worthy of further exploration.

2021年2月20日 星期六 上午9:56 | | | Andrei Khrennikov | | | quant-ph updates on arXiv.org |

In quantum physics, the notion of contextuality has a variety of interpretations which are typically associated with the names of their inventors, say Bohr, Bell, Kochen and Specker, and recently Dzhafarov. In fact, Bohr was the first who pointed to contextuality of quantum measurements as a part of formulation of his principle of complementarity. (Instead of “contextuality”, he considered dependence on “experimental conditions.”) Unfortunately, the contextuality counterpart of the complementarity principle was overshadowed by the issue of incompatibility of observables. And the interest for contextuality of quantum measurements rose again only in connection with the Bell inequality. The original Bohr’s contextuality, as contextuality of each quantum measurement, was practically forgotten. It was highlighted in the works of the author of this paper, with applications both to physics and cognition. In this note, the theory of open quantum systems is applied to formalization of Bohr’s contextuality within the the scheme of indirect measurements. This scheme is widely used in quantum information theory and it leads to the theory of quantum instruments (Davis-Lewis-Ozawa). In this scheme, Bohr’s viewpoint on contextuality of quantum measurements is represented in the formal mathematical framework.

The Wavefunction of Continuous-Time Recurrent Neural Networks. (arXiv:2102.09399v1 [cs.LG])

2021年2月20日 星期六 上午9:56 | | | Ikjyot Singh Kohli, Michael C. Haslam | | | quant-ph updates on arXiv.org |

In this paper, we explore the possibility of deriving a quantum wavefunction for continuous-time recurrent neural network (CTRNN). We did this by first starting with a two-dimensional dynamical system that describes the classical dynamics of a continuous-time recurrent neural network, and then deriving a Hamiltonian. After this, we quantized this Hamiltonian on a Hilbert space $\mathbb{H} = L^2(\mathbb{R})$ using Weyl quantization. We then solved the Schrodinger equation which gave us the wavefunction in terms of Kummer’s confluent hypergeometric function corresponding to the neural network structure. Upon applying spatial boundary conditions at infinity, we were able to derive conditions/restrictions on the weights and hyperparameters of the neural network, which could potentially give insights on the the nature of finding optimal weights of said neural networks.

2021年2月20日 星期六 上午9:56 | | | A. D. Correia, H. T. C. Stoof, M. Moortgat | | | quant-ph updates on arXiv.org |

Extended versions of the Lambek Calculus currently used in computational linguistics rely on unary modalities to allow for the controlled application of structural rules affecting word order and phrase structure. These controlled structural operations give rise to derivational ambiguities that are missed by the original Lambek Calculus or its pregroup simplification. Proposals for compositional interpretation of extended Lambek Calculus in the compact closed category of FVect and linear maps have been made, but in these proposals the syntax-semantics mapping ignores the control modalities, effectively restricting their role to the syntax. Our aim is to turn the modalities into first-class citizens of the vectorial interpretation. Building on the directional density matrix semantics, we extend the interpretation of the type system with an extra spin density matrix space. The interpretation of proofs then results in ambiguous derivations being tensored with orthogonal spin states. Our method introduces a way of simultaneously representing co existing interpretations of ambiguous utterances, and provides a uniform framework for the integration of lexical and derivational ambiguity.

2021年2月20日 星期六 上午9:56 | | | gr-qc updates on arXiv.org |

Authors: Sachin Pandey, Narayan Banerjee

This work deals with the violation or retention of symmetries associated with the self-adjoint extension of the Hamiltonian for homogeneous but anisotropic Bianchi I cosmological model. This extension is required to make sure the quantum evolution is unitary. It is found that the scale invariance is lost, but the Noether symmetries are preserved.

2021年2月20日 星期六 上午9:56 | | | gr-qc updates on arXiv.org |

Authors: Sander M Vermeulen, Lorenzo Aiello, Aldo Ejlli, William L Griffiths, Alasdair L James, Katherine L Dooley, Hartmut Grote

Theories of quantum gravity based on the holographic principle predict the existence of quantum fluctuations of distance measurements that accumulate and exhibit correlations over macroscopic distances. This paper models an expected signal due to this phenomenology, and details the design and estimated sensitivity of co-located twin table-top 3D interferometers being built to measure or constrain it. The experiment is estimated to be sensitive to displacements $\sim10^{-19}\,\rm{m}/\sqrt{\rm{Hz}}$ in a frequency band between 1 and 250 MHz, surpassing previous experiments and enabling the possible observation of quantum gravity phenomena. The experiment will also be sensitive to MHz gravitational waves and various dark matter candidates.

Quick thinking: how Einstein did (and did not) refute the ether frame of reference

2021年2月20日 星期六 上午8:00 | | | Latest Results for Synthese |

**Abstract**

This paper addresses and proposes to resolve a longstanding problem in the philosophy of physics: whether and in what sense Albert Einstein’s *Chasing the Light* thought experiment was significant in the development of the theory of special relativity. Although Einstein granted this thought experiment pride of place in his 1949 *Autobiographical Notes*, philosophers and physicists continue to debate about what, if anything, the experiment establishes. I claim that we ought to think of *Chasing the Light* as Einstein’s first attempt to problematize the very idea of the electromagnetic ether frame, and that it thereby contributed to his eventual adoption of one of special relativity’s two foundational axioms: the “light postulate”. This interpretation requires the assumption that Einstein had presupposed special relativity’s other axiom, the “principle of relativity”, when initially considering *Chasing the Light*. This argument is novel insofar as it provides evidence that such a presupposition by Einstein is both conceptually and historically plausible. Moreover, this paper directly challenges John D. Norton’s compelling claim that *Chasing the Light* is best understood as a refutation of emission theories of light propagation; while both interpretations of the experiment are conceptually coherent, I argue that the interpretation found in this paper is supported more straightforwardly by historical evidence.

The visibility of philosophy of science in the sciences, 1980–2018

2021年2月19日 星期五 上午8:00 | | | Latest Results for Synthese |

**Abstract**

In this paper, we provide a macro level analysis of the visibility of philosophy of science in the sciences over the last four decades. Our quantitative analysis of publications and citations of philosophy of science papers, published in 17 main journals representing the discipline, contributes to the longstanding debate on the influence of philosophy of science on the sciences. It reveals the global structure of relationships that philosophy of science maintains with science, technology, engineering and mathematics (STEM) and social sciences and humanities (SSH) fields. Explored at the level of disciplines, journals and authors, this analysis of the relations between philosophy of science and a large and diversified array of disciplines allows us to answer several questions: what is the degree of openness of various disciplines to the specialized knowledge produced in philosophy of science? Which STEM and SSH fields and journals have privileged ties with philosophy of science? What are the characteristics, in terms of citation and publication patterns, of authors who get their philosophy of science papers cited outside their field? Complementing existing qualitative inquiries on the influence of specific authors, concepts or topics of philosophy of science, the bibliometric approach proposed in this paper offers a comprehensive portrait of the multiple relationships that links philosophy of science to the sciences.

2021年2月18日 星期四 下午6:00 | | | Zhibo Hou, Yan Jin, Hongzhen Chen, Jun-Feng Tang, Chang-Jiang Huang, Haidong Yuan, Guo-Yong Xiang, Chuan-Feng Li, and Guang-Can Guo | | | PRL: General Physics: Statistical and Quantum Mechanics, Quantum Information, etc. |

Author(s): Zhibo Hou, Yan Jin, Hongzhen Chen, Jun-Feng Tang, Chang-Jiang Huang, Haidong Yuan, Guo-Yong Xiang, Chuan-Feng Li, and Guang-Can Guo

The Heisenberg scaling, which scales as N−1 in terms of the number of particles or T−1 in terms of the evolution time, serves as a fundamental limit in quantum metrology. Better scalings, dubbed as “super-Heisenberg scaling,” however, can also arise when the generator of the parameter involves many-…

[Phys. Rev. Lett. 126, 070503] Published Thu Feb 18, 2021

Probing theoretical statements with thought experiments

2021年2月18日 星期四 上午8:00 | | | Latest Results for Synthese |

**Abstract**

Many thought experiments (TEs) are used to probe theoretical statements. One crucial strategy for doing this, or so I will argue, is the following. A TE reveals an inconsistency in part of our previously held, sometimes empirically well-established, theoretical statements. A TEer or her critic then proposes a resolution in the form of a conjecture, a hypothesis that merits further investigation. To explore this characterisation of the epistemic function of such TEs, I clarify the nature of the inconsistencies revealed by TEs, and how TEs reveal and resolve them. I argue that this can be done without settling the question of which cognitive processes are involved in performing a TE; be they propositional or non-propositional. The upshot is that TEs’ reliability, like real experiments, is to be found, in part, in their replicability by the epistemic community, not in their cognitive underpinnings.

2021年2月17日 星期三 下午2:43 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Dewar, Neil (2020) On Absolute Units. [Preprint]

A critical analysis of Markovian monism

2021年2月16日 星期二 上午8:00 | | | Latest Results for Synthese |

**Abstract**

Free Energy Principle underlies a unifying framework that integrates theories of origins of life, cognition, and action. Recently, FEP has been developed into a Markovian monist perspective (Friston et al. in BC 102: 227–260, 2020). The paper expresses scepticism about the validity of arguments for Markovian monism. The critique is based on the assumption that Markovian models are scientific models, and while we may defend ontological theories about the nature of scientific models, we could not read off metaphysical theses about the nature of target systems (self-organising conscious systems, in the present context) from our theories of nature of scientific models (Markov blankets). The paper draws attention to different ways of understanding Markovian models, as material entities, fictional entities, and mathematical structures. I argue that none of these interpretations contributes to the defence of a metaphysical stance (either in terms of neutral monism or reductive physicalism). This is because scientific representation is a sophisticated process, and properties of Markovian models—such as the property of being neither physical nor mental—could not be projected onto their targets to determine the ontological properties of targets easily.

Mathematical Anti-Realism and Explanatory Structure

2021年2月16日 星期二 上午7:17 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Whittle, Bruno (2021) Mathematical Anti-Realism and Explanatory Structure. [Preprint]

Sensitive spin seeks single magnon

2021年2月15日 星期一 上午8:00 | | | Sophia E. Economou | | | Nature Physics – Issue – nature.com science feeds |

Nature Physics, Published online: 15 February 2021; doi:10.1038/s41567-021-01176-5

A quantum dot has been used to detect a single excitation among the tens of thousands of atomic nuclear spins comprising it. This result is an important step towards treating nuclear spins as a quantum memory rather than a troublesome source of noise.

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