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

Authors: David Benisty, Denitsa Staicova

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

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

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

Authors: Roberto Emparan, Marija Tomašević

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

Are Points (Necessarily) Unextended?

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

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

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

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

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

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

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

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

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

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

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

The Everett Interpretation: probability

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

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

On the Relation of the Laws of Thermodynamics to Statistical Mechanics

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

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

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

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

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

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

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

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

Authors: Galina Weinstein

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

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

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

Authors: Anandamay Das Bhowmik, Preeti Parashar, Manik Banik

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

Unifying theory of quantum state estimation using past and future information

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

Publication date: Available online 20 July 2021

**Source:** Physics Reports

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

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

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

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

Authors: Atsushi Higuchi, William C. C. Lima

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

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

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

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

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

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

Understanding the Progress of Science

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

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

Testability and Viability: Is Inflationary Cosmology “Scientific”?

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

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

The Constitution of Weyl’s Pure Infinitesimal World Geometry

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

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

What eliminative materialism isn’t

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

**Abstract**

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

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

**Abstract**

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

Consciousness and the Laws of Physics

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

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

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

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

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

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

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

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

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

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

Authors: Karl-Erik Eriksson

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

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

Authors: Indrajit Sen

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

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

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

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

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

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

Authors: Avadhut V. Purohit

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

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

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

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

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

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

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

]]>Sebastian Fortin & Olimpia Lombardi

**Abstract**

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

Authors: Leander Vignero, Sylvia Wenmackers

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

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

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

Approaching probabilistic laws

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

**Abstract**

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

Formulations of Classical Mechanics

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

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

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

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

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

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

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

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

Relational Quantum Mechanics and the PBR Theorem: A Peaceful Coexistence

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

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

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

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

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

Relativistic Constraints on Interpretations of Quantum Mechanics

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

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

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

**Abstract**

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

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

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

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

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

]]>上午9:18 | | | Mirjam Weilenmann, Roger Colbeck | | | quant-ph updates on arXiv.org |

Self-testing usually refers to the task of taking a given set of observed correlations that are assumed to arise via a process that is accurately described by quantum theory, and trying to infer the quantum state and measurements. In other words it is concerned with the question of whether we can tell what quantum black-box devices are doing by looking only at their input-output behaviour and is known to be possible in several cases. Here we introduce a more general question: is it possible to self-test a theory, and, in particular, quantum theory? More precisely, we ask whether within a particular causal structure there are tasks that can only be performed in theories that have the same correlations as quantum mechanics in any scenario. We present a candidate task for such a correlation self-test and analyse it in a range of generalised probabilistic theories (GPTs), showing that none of these perform better than quantum theory. A generalisation of our results showing that all non-quantum GPTs are strictly inferior to quantum mechanics for this task would point to a new way to axiomatise quantum theory, and enable an experimental test that simultaneously rules out such GPTs.

Discovery of the Relativistic Schr\”odinger Equation. (arXiv:2012.12467v4 [physics.hist-ph] UPDATED)

上午9:18 | | | Kamal Barley, José Vega-Guzmán, Andreas Ruffing, Sergei K. Suslov | | | quant-ph updates on arXiv.org |

We discuss the discovery of the relativistic wave equation for a spin-zero charged particle in the Coulomb field by Erwin Schr\”odinger (and elaborate on why he didn’t publish it).

上午9:18 | | | Ravishankar Ramanathan, Yuan Liu, Paweł Horodecki | | | quant-ph updates on arXiv.org |

The Kochen-Specker (KS) theorem is a fundamental result in quantum foundations that has spawned massive interest since its inception. We present state-independent non-contextuality inequalities with large violations, in particular, we exploit a connection between Kochen-Specker proofs and pseudo-telepathy games to show KS proofs in Hilbert spaces of dimension $d \geq 2^{17}$ with the ratio of quantum value to classical bias being $O(\sqrt{d}/\log d)$. We study the properties of this KS set and show applications of the large violation. It has been recently shown that Kochen-Specker proofs always consist of substructures of state-dependent contextuality proofs called $01$-gadgets or bugs. We show a one-to-one connection between $01$-gadgets in $\mathbb{C}^d$ and Hardy paradoxes for the maximally entangled state in $\mathbb{C}^d \otimes \mathbb{C}^d$. We use this connection to construct large violation $01$-gadgets between arbitrary vectors in $\mathbb{C}^d$, as well as novel Hardy paradoxes for the maximally entangled state in $\mathbb{C}^d \otimes \mathbb{C}^d$, and give applications of these constructions. As a technical result, we show that the minimum dimension of the faithful orthogonal representation of a graph in $\mathbb{R}^d$ is not a graph monotone, a result that that may be of independent interest.

上午9:18 | | | gr-qc updates on arXiv.org |

Authors: Taishi Katsuragawa, Shinya Matsuzaki, Kensuke Homma

We propose a method to probe chameleon particles predicted in the $F(R)$ gravity as a model of the modified gravity based on the concept of a stimulated pulsed-radar collider. We analyze the chameleon mechanism induced by an ambient environment consisting of focused photon beams and a dilute gas surrounding a place where stimulated photon-photon scatterings occur. We then discuss how to extract the characteristic feature of the chameleon signal. We find that a chameleon with the varying mass around $(0.1-1)\,\mu$eV in a viable model of the $F(R)$ gravity is testable by searching for the steep pressure dependence of the 10th-power for the signal yield.

Initial Results from the LIGO Newtonian Calibrator. (arXiv:2107.00141v1 [gr-qc])

上午9:18 | | | gr-qc updates on arXiv.org |

Authors: Michael P. Ross, Timesh Mistry, Laurence Datrier, Jeff Kissel, Krishna Venkateswara, Colin Weller, Kavic Kumar, Charlie Hagedorn, Eric Adelberger, John Lee, Erik Shaw, Patrick Thomas, David Barker, Filiberto Clara, Bubba Gateley, Tyler M. Guidry, Ed Daw, Martin Hendry, Jens Gundlach

The precise calibration of the strain readout of the LIGO gravitational wave observatories is paramount to the accurate interpretation of gravitational wave events. This calibration is traditionally done by imparting a known force on the test masses of the observatory via radiation pressure. Here we describe the implementation of an alternative calibration scheme: the Newtonian Calibrator. This system uses a rotor consisting of both quadrupole and hexapole mass distributions to apply a time-varying gravitational force on one of the observatory’s test masses. The force produced by this rotor can be predicted to $<1\%$ relative uncertainty and is well-resolved in the readout of the observatory. This system currently acts as a cross-check of the existing absolute calibration system.

The Strong Emergence of Molecular Structure

上午2:02 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Seifert, Vanessa A. (2020) The Strong Emergence of Molecular Structure. [Preprint]

The Local versus the Global in the History of Relativity: The Case of Belgium

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

ten Hagen, Sjang L. (2021) The Local versus the Global in the History of Relativity: The Case of Belgium. Science in Context, 33 (3). pp. 227-250.

Humeanism in light of quantum gravity

2021年7月2日 星期五 上午8:00 | | | Latest Results for Synthese |

**Abstract**

Quantum Theory and Humeanism have long been thought to be incompatible due to the irreducibility of the correlations involved in entangled states. In this paper, we reconstruct the tension between Humeanism and entanglement via the concept of causal structure, and provide a philosophical introduction to the ER=EPR conjecture. With these tools, we then show how the concept of causal structure and the ER=EPR conjecture allow us to resolve the conflict between Humeanism and entanglement.

From structure preserving representation to making worlds with symbols

2021年7月1日 星期四 上午8:00 | | | Latest Results for Synthese |

This article does not provide any content.

Fundamental non-qualitative properties

2021年7月1日 星期四 上午8:00 | | | Latest Results for Synthese |

**Abstract**

The distinction between qualitative and non-qualitative properties should be familiar from discussions of the principle of the identity of indiscernibles: two otherwise exactly similar individuals, Castor and Pollux, might share all their qualitative properties yet differ with respect to their non-qualitative properties—for while Castor has the property *being identical to Castor*, Pollux does not. But while this distinction is familiar, there has not been much critical attention devoted to spelling out its precise nature. I argue that the class of non-qualitative properties is broader than it is often taken to be. When properly construed, it will not only include properties such as *being identical to Castor*, which somehow make reference to particular individuals, it will also include more general properties such as identity, composition, set membership, as well as various peculiarly ontological properties. Given that some of these more general properties help to explain objective similarity, we have reason to believe that there are fundamental non-qualitative properties.

2021年7月1日 星期四 上午8:00 | | | Latest Results for Synthese |

**Abstract**

Super-Humeanism is an even more parsimonious ontology than Lewisian standard Humean metaphysics in that it rejects intrinsic properties (local qualties). There are point objects, but all there is to them are their relative positions (distance relations) and the change of them. Everything else supervenes on the Humean mosaic thus conceived. Hence, dynamical parameters (such as mass, charge, energy, a wave-function, etc.) come in on a par with the laws through their position in the best system. The paper sets out how Super-Humeanism has the conceptual means to reject van Inwagen’s consequence argument not by taking the laws to depend on us (as on standard Humean metaphysics), but by taking the initial values of the dynamical parameters that enter into the laws to be dependent on the motions that actually occur in the universe, including the motions of human bodies. The paper spells out the advantages of this proposal.

A dynamical systems approach to causation

2021年7月1日 星期四 上午8:00 | | | Latest Results for Synthese |

**Abstract**

Our approach aims at accounting for causal claims in terms of how the physical states of the underlying dynamical system evolve with time. Causal claims assert connections between two sets of physicals states—their truth depends on whether the two sets in question are genuinely connected by time evolution such that physical states from one set evolve with time into the states of the other set. We demonstrate the virtues of our approach by showing how it is able to account for typical causes, causally relevant factors, being ‘the’ cause, and cases of overdetermination and causation by absences.

Entanglement and indistinguishability in a quantum ontology of properties

2021年6月30日 星期三 上午9:47 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Fortin, Sebastian and Lombardi, Olimpia (2021) Entanglement and indistinguishability in a quantum ontology of properties. [Preprint]

2021年6月30日 星期三 上午9:46 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Kuehn, Reimer and Lavis, David and Frigg, Roman (2021) Becoming Large, Becoming Infinite: The Anatomy of Thermal Physics and Phase Transitions in Finite Systems. [Preprint]

Better appreciating the scale of it (Lemaître and de Sitter at the BAAS Centenary)

2021年6月30日 星期三 上午9:44 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

De Baerdemaeker, Siska and Schneider, Mike D. (2021) Better appreciating the scale of it (Lemaître and de Sitter at the BAAS Centenary). [Preprint]

Modal Ω-Logic: Automata, Neo-Logicism, and Set-Theoretic Realism

2021年6月30日 星期三 上午7:34 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Khudairi, Hasen (2019) Modal Ω-Logic: Automata, Neo-Logicism, and Set-Theoretic Realism. [Preprint]

On ‘Experiencing Time’ – a response to Simon Prosser

2021年6月28日 星期一 下午4:28 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Deng, Natalja (2018) On ‘Experiencing Time’ – a response to Simon Prosser. Inquiry: an interdisciplinary journal of philosophy. ISSN 0020-174X

One thing after another: why the passage of time is not an illusion

2021年6月28日 星期一 下午4:27 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Deng, Natalja (2019) One thing after another: why the passage of time is not an illusion. pp. 3-15.

Plenty to come: making sense of Correia’s and Rosenkranz’s growing block

2021年6月28日 星期一 下午4:26 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Deng, Natalja (2021) Plenty to come: making sense of Correia’s and Rosenkranz’s growing block. [Preprint]

Violation of Bell Inequalities: Mapping the Conceptual Implications

2021年6月28日 星期一 下午4:25 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Drummond, Brian (2021) Violation of Bell Inequalities: Mapping the Conceptual Implications. International Journal of Quantum Foundations, 7 (3). pp. 47-78.

Quantum advantage for computations with limited space

2021年6月28日 星期一 上午8:00 | | | Sarah Sheldon | | | Nature Physics – Issue – nature.com science feeds |

Nature Physics, Published online: 28 June 2021; doi:10.1038/s41567-021-01271-7

In general, it isn’t known when a quantum computer will have an advantage over a classical device. Now it’s proven that computers with limited working memory are more powerful if they are quantum.

Introducing Quantum Entanglement to First-Year Students: Resolving the Trilemma (arXiv:2106.12043 (physics))

Authors: W.M. Stuckey, Timothy McDevitt, Michael Silberstein

While quantum mechanics (QM) is covered at length in introductory physics textbooks, the concept of quantum entanglement is typically not covered at all, despite its importance in the rapidly growing area of quantum information science and its extensive experimental confirmation. Thus, physics educators are left to their own devices as to how to introduce this important concept. Regardless of how a physics educator chooses to introduce quantum entanglement, they face a trilemma involving its mysterious Bell-inequality-violating correlations. They can compromise on the the completeness of their introduction and simply choose not to share that fact. They can frustrate their more curious students by introducing the mystery and simply telling them that the QM formalism with its associated (equally mysterious) conservation law maps beautifully to the experiments, so there is nothing else that needs to be said. Or, they can compromise the rigor of their presentation and attempt to resolve the mystery by venturing into the metaphysical quagmire of competing QM interpretations. Herein, we resolve this trilemma in precisely the same way that Einstein resolved the mysteries of time dilation and length contraction that existed in the late nineteenth century. That is, we resort to “principle” explanation based on the mathematical consequences of “empirically discovered” facts. Indeed, our principle account of quantum entanglement is even based on the same principle Einstein used, i.e., the relativity principle or “no preferred reference frame.” Thus, this principle resolution of the trilemma is as complete, satisfying, analytically rigorous, and accessible as the standard introduction of special relativity for first-year physics students.

]]>上午9:37 | | | Lorenzo Leone, Salvatore F. E. Oliviero, Alioscia Hamma | | | quant-ph updates on arXiv.org |

We introduce a novel measure for the quantum property commonly known as $magic$ by considering the R\’enyi entropy of the probability distribution associated to a pure quantum state given by the square of the expectation value of Pauli strings in that state. We show that this is a good measure of magic from the point of view of resource theory and show bounds with other known measures of magic. The R\’enyi entropy of magic has the advantage of being easily computable because it does not need a minimization procedure. We define the magic power of a unitary operator as the average entropy of magic attainable by the action of this operator on the magic-free states, that is, stabilizer states, and show the basic properties of this quantity. As an application, we show that the magic power is intimately connected to out-of-time-order correlation functions and that maximal levels of magic are necessary for quantum chaos.

Path Integrals: From Quantum Mechanics to Photonics. (arXiv:2105.00948v2 [quant-ph] UPDATED)

上午9:37 | | | Charles W. Robson, Yaraslau Tamashevich, Tapio T. Rantala, Marco Ornigotti | | | quant-ph updates on arXiv.org |

The path integral formulation of quantum mechanics, i.e., the idea that the evolution of a quantum system is determined as a sum over all the possible trajectories that would take the system from the initial to its final state of its dynamical evolution, is perhaps the most elegant and universal framework developed in theoretical physics, second only to the Standard Model of particle physics. In this tutorial, we retrace the steps that led to the creation of such a remarkable framework, discuss its foundations, and present some of the classical examples of problems that can be solved using the path integral formalism, as a way to introduce the readers to the topic, and help them get familiar with the formalism. Then, we focus our attention on the use of path integrals in optics and photonics, and discuss in detail how they have been used in the past to approach several problems, ranging from the propagation of light in inhomogeneous media, to parametric amplification, and quantum nonlinear optics in arbitrary media. To complement this, we also briefly present the Path Integral Monte Carlo (PIMC) method, as a valuable computational resource for condensed matter physics, and discuss its potential applications and advantages if used in photonics.

Quantum Computing for Location Determination. (arXiv:2106.11751v2 [quant-ph] UPDATED)

上午9:37 | | | Ahmed Shokry, Moustafa Youssef | | | quant-ph updates on arXiv.org |

Quantum computing provides a new way for approaching problem solving, enabling efficient solutions for problems that are hard on classical computers. It is based on leveraging how quantum particles behave. With researchers around the world showing quantum supremacy and the availability of cloud-based quantum computers with free accounts for researchers, quantum computing is becoming a reality. In this paper, we explore both the opportunities and challenges that quantum computing has for location determination research. Specifically, we introduce an example for the expected gain of using quantum algorithms by providing an efficient quantum implementation of the well-known RF fingerprinting algorithm and run it on an instance of the IBM Quantum Experience computer. The proposed quantum algorithm has a complexity that is exponentially better than its classical algorithm version, both in space and running time. We further discuss both software and hardware research challenges and opportunities that researchers can build on to explore this exciting new domain.

Boltzmann’s Concept of Reality. (arXiv:physics/0701308v2 [physics.hist-ph] UPDATED)

上午9:37 | | | physics.hist-ph updates on arXiv.org |

Authors: Marcelo B. Ribeiro (1), Antonio A. P. Videira (2) ((1) Physics Institute, Universidade Federal do Rio de Janeiro – UFRJ, Brazil, (2) Department of Philosophy, Universidade do Estado do Rio de Janeiro – UERJ, Brazil)

In this article we describe and analyze the concept of reality developed by the Austrian theoretical physicist Ludwig Boltzmann. It is our thesis that Boltzmann was fully aware that reality could, and actually was, described by different points of view. In spite of this, Boltzmann did not renounce the idea that reality is real. We also discuss his main motivations to be strongly involved with philosophy of science, as well as further developments made by Boltzmann himself of his main philosophical ideas, namely scientific theories as images of Nature and its consequences. We end the paper with a discussion about the modernity of Boltzmann’s philosophy of science.

上午9:37 | | | physics.hist-ph updates on arXiv.org |

Authors: Charles T. Sebens

Within quantum chemistry, the electron clouds that surround nuclei in atoms and molecules are sometimes treated as clouds of probability and sometimes as clouds of charge. These two roles, tracing back to Schr\”odinger and Born, are in tension with one another but are not incompatible. Schr\”odinger’s idea that the nucleus of an atom is surrounded by a spread-out electron charge density is supported by a variety of evidence from quantum chemistry, including two methods that are used to determine atomic and molecular structure: the Hartree-Fock method and density functional theory. Taking this evidence as a clue to the foundations of quantum physics, Schr\”odinger’s electron charge density can be incorporated into many different interpretations of quantum mechanics (and extensions of such interpretations to quantum field theory).

上午9:37 | | | gr-qc updates on arXiv.org |

Authors: Juan F. Pedraza, Andrea Russo, Andrew Svesko, Zachary Weller-Davies

Holographic entanglement entropy was recently recast in terms of Riemannian flows or ‘bit threads’. We consider the Lorentzian analog to reformulate the ‘complexity=volume’ conjecture using Lorentzian flows — timelike vector fields whose minimum flux through a boundary subregion is equal to the volume of the homologous maximal bulk Cauchy slice. By the nesting of Lorentzian flows, holographic complexity is shown to obey a number of properties. Particularly, the rate of complexity is bounded below by conditional complexity, describing a multi-step optimization with intermediate and final target states. We provide multiple explicit geometric realizations of Lorentzian flows in AdS backgrounds, including their time-dependence and behavior near the singularity in a black hole interior. Conceptually, discretized flows are interpreted as Lorentzian threads or ‘gatelines’. Upon selecting a reference state, complexity thence counts the minimum number of gatelines needed to prepare a target state described by a tensor network discretizing the maximal volume slice, matching its quantum information theoretic definition. We point out that suboptimal tensor networks are important to fully characterize the state, leading us to propose a refined notion of complexity as an ensemble average. The bulk symplectic potential provides a specific ‘canonical’ thread configuration characterizing perturbations around arbitrary CFT states. Consistency of this solution requires the bulk satisfy the linearized Einstein’s equations, which are shown to be equivalent to the holographic first law of complexity, thereby advocating for a principle of ‘spacetime complexity’. Lastly, we argue Lorentzian threads provide a notion of emergent time. This article is an expanded and detailed version of [arXiv:2105.12735], including several new results.

上午9:37 | | | gr-qc updates on arXiv.org |

Authors: M. Gasperini

We present a short introduction to a non-standard cosmological scenario motivated by the duality symmetries of string theory, in which the big bang singularity is replaced with a “big bounce” at high but finite curvature. The bouncing epoch is prepared by a long (possibly infinitely extended) phase of cosmic evolution, starting from an initial state asymptotically approaching the string perturbative vacuum.

Quantization of Gravity in the Black Hole Background. (arXiv:2106.01966v2 [hep-th] UPDATED)

上午9:37 | | | gr-qc updates on arXiv.org |

Authors: Renata Kallosh, Adel A. Rahman

We perform a covariant (Lagrangian) quantization of perturbative gravity in the background of a Schwarzschild black hole. The key tool is a decomposition of the field into spherical harmonics. We fix Regge-Wheeler gauge for modes with angular momentum quantum number $l \geq 2$, while for low multipole modes with $l$ $=$ $0$ or $1$ — for which Regge-Wheeler gauge is inapplicable — we propose a set of gauge fixing conditions which are 2D background covariant and perturbatively well-defined. We find that the corresponding Faddeev-Popov ghosts are non-propagating for the $l\geq2$ modes, but are in general nontrivial for the low multipole modes with $l = 0,1$. However, in Schwarzschild coordinates, all time derivatives acting on the ghosts drop from the action and the low multipole ghosts have instantaneous propagators. Up to possible subtleties related to quantizing gravity in a space with a horizon, Faddeev’s theorem suggests the possibility of an underlying canonical (Hamiltonian) quantization with a manifestly ghost-free Hilbert space.

上午9:37 | | | gr-qc updates on arXiv.org |

Authors: Faizuddin Ahmed

In this paper, the relativistic quantum dynamics of a scalar particle under the effect of Lorentz symmetry violation determined by a tensor $(K_{F})_{\mu\,\nu\,\alpha\,\beta}$ out of the Standard Model Extension is investigated. We see that the bound-state solution of the modified Klein-Gordon equation can be obtained, and the spectrum of energy and the wave function depends on the Lorentz symmetry breaking parameters

String theory, Einstein, and the identity of physics: Theory assessment in absence of the empirical

2021年6月25日 星期五 上午3:16 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

van Dongen, Jeroen (2021) String theory, Einstein, and the identity of physics: Theory assessment in absence of the empirical. [Preprint]

2021年6月25日 星期五 上午3:15 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Brunet, Tyler D. P. (2021) Local Causation. [Preprint]

Quantum pointillism with relational identity

2021年6月24日 星期四 上午8:00 | | | Latest Results for Synthese |

**Abstract**

The feasibility of establishing a proper notion of a *distinguishable object* in the context of the de Broglie–Bohm approach to quantum mechanics seems, at first sight, uncontroversial by virtue of the fact that this theory can supposedly be interpreted in terms of a system of objective particles distinguished by individuating properties. However, after conducting a critical revision and evaluation of this trivial interpretation, and having assessed different alternatives that have been proposed in recent literature, I argue that within this theory an appropriate notion of a *distinguishable object* can only be articulated by means of the following theoretical and metaphysical strategies: firstly, by appealing to a pre-existing, symmetrized Bohmian framework that is empirically indistinguishable but physically distinguishable from the standard Bohmian formulation; and secondly, by suggesting a different interpretation of this symmetrized formulation based upon a relational notion of the *distinguishable object* that can only be appropriately conceived from a structuralist point of view.

Scattering and Perturbation Theory for Discrete-Time Dynamics

2021年6月23日 星期三 下午6:00 | | | Alessandro Bisio, Nicola Mosco, and Paolo Perinotti | | | PRL: General Physics: Statistical and Quantum Mechanics, Quantum Information, etc. |

Author(s): Alessandro Bisio, Nicola Mosco, and Paolo Perinotti

We present a systematic treatment of scattering processes for quantum systems whose time evolution is discrete. We define and show some general properties of the scattering operator, in particular the conservation of quasienergy which is defined only modulo 2π. Then we develop two perturbative techn…

[Phys. Rev. Lett. 126, 250503] Published Wed Jun 23, 2021

Quantum Simulation of Three-Body Interactions in Weakly Driven Quantum Systems

2021年6月23日 星期三 下午6:00 | | | Francesco Petiziol, Mahdi Sameti, Stefano Carretta, Sandro Wimberger, and Florian Mintert | | | PRL: General Physics: Statistical and Quantum Mechanics, Quantum Information, etc. |

Author(s): Francesco Petiziol, Mahdi Sameti, Stefano Carretta, Sandro Wimberger, and Florian Mintert

The realization of effective Hamiltonians featuring many-body interactions beyond pairwise coupling would enable the quantum simulation of central models underpinning topological physics and quantum computation. We overcome crucial limitations of perturbative Floquet engineering and discuss the high…

[Phys. Rev. Lett. 126, 250504] Published Wed Jun 23, 2021

2021年6月23日 星期三 上午5:16 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Belot, Gordon (2021) Gravity and GRACE. [Preprint]

How do electrons move in atoms? From the Bohr model to quantum mechanics

2021年6月23日 星期三 上午5:12 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Gao, Shan (2021) How do electrons move in atoms? From the Bohr model to quantum mechanics. One hundred years of the Bohr atom: Proceedings from a conference (Edited by F. Aaserud and H. Kragh). Scientia Danica. Series M: Mathematica et physica, vol. 1., 2015. pp. 450-464. ISSN 1904-5514

On the Connection Between Quantum Probability and Geometry

2021年6月23日 星期三 上午5:10 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Holik, Federico (2021) On the Connection Between Quantum Probability and Geometry. Quanta.

Beauty, Truth and Understanding

2021年6月23日 星期三 上午5:09 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Milena, Ivanova (2020) Beauty, Truth and Understanding. [Preprint]

Scientific Perspectivism and the Methodology of Modern Mathematical Physics

2021年6月23日 星期三 上午5:08 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Stemeroff, Noah (2021) Scientific Perspectivism and the Methodology of Modern Mathematical Physics. [Preprint]

Do molecules have structure in isolation? How models can provide the answer

2021年6月20日 星期日 下午4:12 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Seifert, Vanessa A. (2021) Do molecules have structure in isolation? How models can provide the answer. [Preprint]

Induced osmotic vorticity in the quantum hydrodynamical picture (arXiv:2106.13225 [quant-ph])

Authors: C Dedes

A nonlinear wave mechanical equation is proposed by inserting an imaginary quantum potential into the Schrödinger equation. An explicit expression for its solution is given under certain assumptions and it is shown that it entails attenuation related effects as non-unitary evolution, non-exponential quantum decay and entropy production. In the quantum hydrodynamical formulation the existence of circulation effects for the osmotic velocity field is established. Finally, a time-invariant equation for the probability density is derived, analogous to the tensor Lighthill equation in aeroacoustics, which admits both retarded and advanced solutions.

]]>This short article concentrates on the conceptual aspects of the violation of Bell inequalities, and acts as a map to the 265 cited references. The article outlines (a) relevant characteristics of quantum mechanics, such as statistical balance and entanglement, (b) the thinking that led to the derivation of the original Bell inequality, and (c) the range of claimed implications, including realism, locality and others which attract less attention. The main conclusion is that violation of Bell inequalities appears to have some implications for the nature of physical reality, but that none of these are definite. The violations constrain possible prequantum (underlying) theories, but do not rule out the possibility that such theories might reconcile at least one understanding of locality and realism to quantum mechanical predictions. Violation might reflect, at least partly, failure to acknowledge the contextuality of quantum mechanics, or that data from different probability spaces have been inappropriately combined. Many claims that there are definite implications reflect one or more of (i) imprecise non-mathematical language, (ii) assumptions inappropriate in quantum mechanics, (iii) inadequate treatment of measurement statistics and (iv) underlying philosophical assumptions.

]]>It is possible to construct a classical, macroscopic system which has a mathematical structure that is exactly the same as that of a quantum mechanical system and which can be put into a state which has exactly the same probability predictions as a quantum mechanical with entanglement. This paper presents a simple example, including a way in which the system can be measured to violate Bell’s inequalities. This classical simulation of a quantum system helps us to see what aspects of quantum mechanical systems are truly nonclassical.

]]>上午10:21 | | | I. Jubb | | | quant-ph updates on arXiv.org |

In relativistic Quantum Field Theory (QFT) ideal measurements of certain observables are physically impossible without violating causality. This prompts two questions: i) can a given observable be ideally measured in QFT, and ii) if not, in what sense can it be measured? Here we formulate a necessary and sufficient condition that any measurement, and more generally any state update (quantum operation), must satisfy to respect causality. Our focus is scalar QFT, although our results should be applicable to observables in fermionic QFT. We argue that for unitary `kicks’ and operations involving 1-parameter families of Kraus operators, e.g. Gaussian measurements, the only causal observables are smeared fields and the identity – the basic observables in QFT. We provide examples with more complicated operators such as products of smeared fields, and show that the associated state updates are acausal, and hence impossible. Despite this, one can still recover expectation values of such operators, and we show how to do this using only causal measurements of smeared fields.

Contextuality without incompatibility. (arXiv:2106.09045v1 [quant-ph])

上午10:21 | | | John H. Selby, David Schmid, Elie Wolfe, Ana Belén Sainz, Ravi Kunjwal, Robert W. Spekkens | | | quant-ph updates on arXiv.org |

The existence of incompatible measurements is often believed to be a feature of quantum theory which signals its inconsistency with any classical worldview. To prove the failure of classicality in the sense of Kochen-Specker noncontextuality, one does indeed require sets of incompatible measurements. However, a more broadly applicable and more permissive notion of classicality is the existence of a generalized-noncontextual ontological model. In particular, this notion can imply constraints on the representation of outcomes even within a single nonprojective measurement. We leverage this fact to demonstrate that measurement incompatibility is neither necessary nor sufficient for proofs of the failure of generalized noncontextuality. Furthermore, we show that every proof of the failure of generalized noncontextuality in a prepare-measure scenario can be converted into a proof of the failure of generalized noncontextuality in a corresponding scenario with no incompatible measurements.

Quantum Entanglement of Free Particles. (arXiv:2106.09356v1 [quant-ph])

上午10:21 | | | Roumen Tsekov | | | quant-ph updates on arXiv.org |

The Schrodinger equation is solved for many free particles and their quantum entanglement is studied via correlation analysis. Converting the Schrodinger equation in the Madelung hydrodynamic-like form, the quantum mechanics is extended to open quantum systems by adding Ohmic friction forces. The dissipative evolution confirms correlation decay over time, but a new integral of motion is discovered, being appropriate for storing everlasting quantum information.

How to administer an antidote to Schr\”{o}dinger’s cat. (arXiv:2106.09705v1 [quant-ph])

上午10:21 | | | Juan-Rafael Álvarez, Mark IJspeert, Oliver Barter, Ben Yuen, Thomas D. Barrett, Dustin Stuart, Jerome Dilley, Annemarie Holleczek, Axel Kuhn | | | quant-ph updates on arXiv.org |

In his 1935 Gedankenexperiment, Erwin Schr\”{o}dinger imagined a poisonous substance which has a 50% probability of being released, based on the decay of a radioactive atom. As such, the life of the cat and the state of the poison become entangled, and the fate of the cat is determined upon opening the box. We present an experimental technique that keeps the cat alive on any account. This method relies on the time-resolved Hong-Ou-Mandel effect: two long, identical photons impinging on a beam splitter always bunch in either of the outputs. Interpreting the first photon detection as the state of the poison, the second photon is identified as the state of the cat. Even after the collapse of the first photon’s state, we show their fates are intertwined through quantum interference. We demonstrate this by a sudden phase change between the inputs, administered conditionally on the outcome of the first detection, which steers the second photon to a pre-defined output and ensures that the cat is always observed alive.

Granular: “Stochastic space-time and quantum theory”. (arXiv:1601.07171v13 [quant-ph] UPDATED)

上午10:21 | | | Carlton Frederick | | | quant-ph updates on arXiv.org |

In an earlier paper, a stochastic model had been presented for the Planck-scale nature of space-time. From it, many features of quantum mechanics and relativity were derived. But as mathematical points have no extent, the stochastic manifold cannot be tessellated with points (if the points are independently mobile) and so a granular model is required. As grains have orientations as well as positions, spinors (or quaternians) are required to describe them, resulting in phenomena as described by the Dirac equation. We treat both space and time stochastically and thus require a new interpretation of time to prevent an object being in multiple places at the same time. As the grains do have a definite volume, a mechanism is required to create and annihilate grains (without leaving gaps in space-time) as the universe, or parts thereof, expands or contracts. Making the time coordinate complex provides a mechanism. From geometric considerations alone, both the General Relativity field equations (the master equations of Relativity) and the Schr\”odinger equation (the master equation of quantum mechanics) are produced. Finally, to preserve the constancy of the volume element even internal to a mass, we propose a rolled-up fifth-dimension which is non-zero only in the presence of mass or energy.

上午10:21 | | | Albert Benseny, Klaus Mølmer | | | quant-ph updates on arXiv.org |

Adiabatic passage employs a slowly varying time-dependent Hamiltonian to control the evolution of a quantum system along the Hamiltonian eigenstates. For processes of finite duration, the exact time evolving state may deviate from the adiabatic eigenstate at intermediate times, but in numerous applications it is observed that this deviation reaches a maximum and then decreases significantly towards the end of the process. We provide a straightforward theoretical explanation for this welcome but often unappreciated fact. Our analysis emphasizes a separate adiabaticity criterion for high fidelity state-to-state transfer and it points to new effective shortcut strategies for near adiabatic dynamics.

Genuine Multipartite Entanglement in Time. (arXiv:2011.09340v4 [quant-ph] UPDATED)

上午10:21 | | | Simon Milz, Cornelia Spee, Zhen-Peng Xu, Felix A. Pollock, Kavan Modi, Otfried Gühne | | | quant-ph updates on arXiv.org |

While spatial quantum correlations have been studied in great detail, much less is known about the genuine quantum correlations that can be exhibited by temporal processes. Employing the quantum comb formalism, processes in time can be mapped onto quantum states, with the crucial difference that temporal correlations have to satisfy causal ordering, while their spatial counterpart is not constrained in the same way. Here, we exploit this equivalence and use the tools of multipartite entanglement theory to provide a comprehensive picture of the structure of correlations that (causally ordered) temporal quantum processes can display. First, focusing on the case of a process that is probed at two points in time — which can equivalently be described by a tripartite quantum state — we provide necessary as well as sufficient conditions for the presence of bipartite entanglement in different splittings. Next, we connect these scenarios to the previously studied concepts of quantum memory, entanglement breaking superchannels, and quantum steering, thus providing both a physical interpretation for entanglement in temporal quantum processes, and a determination of the resources required for its creation. Additionally, we construct explicit examples of W-type and GHZ-type genuinely multipartite entangled two-time processes and prove that genuine multipartite entanglement in temporal processes can be an emergent phenomenon. Finally, we show that genuinely entangled processes across multiple times exist for any number of probing times.

Capacity of Entanglement in Local Operators. (arXiv:2106.00228v2 [hep-th] UPDATED)

上午10:21 | | | Pratik Nandy | | | quant-ph updates on arXiv.org |

We study the time evolution of the excess value of capacity of entanglement between a locally excited state and ground state in free, massless fermionic theory and free Yang-Mills theory in four spacetime dimensions. Capacity has non-trivial time evolution and is sensitive to the partial entanglement structure, and shows a universal peak at early times. We define a quantity, the normalized “Page time”, which measures the timescale when capacity reaches its peak. This quantity turns out to be a characteristic property of the inserted operator. This firmly establishes capacity as a valuable measure of entanglement structure of an operator, especially at early times similar in spirit to the Renyi entropies at late times. Interestingly, the time evolution of capacity closely resembles its evolution in microcanonical and canonical ensemble of the replica wormhole model in the context of the black hole information paradox.

上午10:21 | | | Clive Cenxin Aw, Francesco Buscemi, Valerio Scarani | | | quant-ph updates on arXiv.org |

Irreversibility is usually captured by a comparison between the process that happens and a corresponding “reverse process”. In the last decades, this comparison has been extensively studied through fluctuation relations. Here we revisit fluctuation relations from the standpoint, suggested decades ago by Watanabe, that the comparison should involve the prediction and the retrodiction on the unique process, rather than two processes. We prove that Bayesian retrodiction underlies every fluctuation relation involving state variables. The retrodictive narrative also brings to the fore the possibility of deriving fluctuation relations based on various statistical divergences, and clarifies some of the traditional assumptions as arising from the choice of a reference prior.

Quantum Gravity Microstates from Fredholm Determinants. (arXiv:2106.09048v1 [hep-th])

上午10:21 | | | gr-qc updates on arXiv.org |

Authors: Clifford V. Johnson

A large class of two dimensional quantum gravity theories of Jackiw-Teitelboim form have a description in terms of random matrix models. Such models, treated fully non-perturbatively, can give an explicit and tractable description of the underlying “microstate” degrees of freedom. They play a prominent role in regimes where the smooth geometrical picture of the physics is inadequate. This is shown using a natural tool for extracting the detailed microstate physics, a Fredholm determinant ${\rm det}(\mathbf{1}{-}\mathbf{ K})$. Its associated kernel $K(E,E^\prime)$ can be defined explicitly for a wide variety of JT gravity theories. To illustrate the methods, the statistics of the first several energy levels of a non-perturbative definition of JT gravity are constructed explicitly using numerical methods, and the full quenched free energy $F_Q(T)$ of the system is computed for the first time. These results are also of relevance to quantum properties of black holes in higher dimensions.

On Planetary Orbits in Entropic Gravity. (arXiv:2106.09155v1 [gr-qc])

上午10:21 | | | gr-qc updates on arXiv.org |

Authors: G. Pérez-Cuéllar, M. Sabido

Starting with an entropy that includes volumetric, area and length terms as well as logarithmic contributions, we derive the corresponding modified Newtonian gravity and derive the expression for planetary orbits. We calculate the shift of the perihelion of Mercury to find bounds to the parameters associated to the modified Newtonian gravity. We compare the parameter associated to the volumetric contribution in the entropy-area relationship with the value derived for galactic rotation curves and the value obtained from the cosmological constant.

Graviton Self-Energy from Gravitons in Cosmology. (arXiv:2103.08547v2 [gr-qc] UPDATED)

上午10:21 | | | gr-qc updates on arXiv.org |

Authors: L. Tan (Florida), N. C. Tsamis (Crete), R. P. Woodard (Florida)

Although matter contributions to the graviton self-energy $-i[\mbox{}^{\mu\nu} \Sigma^{\rho\sigma}](x;x’)$ must be separately conserved on $x^{\mu}$ and ${x’}^{\mu}$, graviton contributions obey the weaker constraint of the Ward identity, which involves a divergence on both coordinates. On a general homogeneous and isotropic background this leads to just four structure functions for matter contributions but nine structure functions for graviton contributions. We propose a convenient parameterization for these nine structure functions. We also apply the formalism to explicit one loop computations of $-i[\mbox{}^{\mu\nu} \Sigma^{\rho\sigma}](x;x’)$ on de Sitter background, one of the contributions from a massless, minimally coupled scalar and the other for the contribution from gravitons in the simplest gauge. We also specialize the linearized, quantum-corrected Einstein equation to the graviton mode function and to the gravitational response to a point mass.

上午10:21 | | | gr-qc updates on arXiv.org |

Authors: Amy Joseph, Juan-Pablo Varela, Molly P. Watts, Tristen White, Yuan Feng, Mohammad Hassan, Michael McGuigan

Cosmology is in an era of rapid discovery especially in areas related to dark energy, dark matter and inflation. Quantum cosmology treats the cosmology quantum mechanically and is important when quantum effects need to be accounted for, especially in the very early Universe. Quantum computing is an emerging new method of computing which excels in simulating quantum systems. Quantum computing may have some advantages when simulating quantum cosmology, especially because the Euclidean action of gravity is unbounded from below, making the implementation of Monte Carlo simulation problematic. In this paper we present several examples of the application of quantum computing to cosmology. These include a dark energy model that is related to Kaluza-Klein theory, dark matter models where the dark sector is described by a self interacting gauge field or a conformal scalar field and an inflationary model with a slow roll potential. We implement quantum computations in the IBM QISKit software framework and show how to apply the Variational Quantum Eigensolver (VQE) and Evolution of Hamiltonian (EOH) algorithms to solve the Wheeler-DeWitt equation that can be used to describe the cosmology in the mini-superspace approximation. We find excellent agreement with classical computing results and describe the accuracy of the different quantum algorithms. Finally we discuss how these methods can be scaled to larger problems going beyond the mini-superspace approximation where the quantum computer may exceed the performance of classical computation.

No Future in Black Holes. (arXiv:2106.03715v2 [hep-th] UPDATED)

上午10:21 | | | gr-qc updates on arXiv.org |

Authors: Malcolm J. Perry

The black hole information paradox has been with us for some time. We outline the nature of the paradox. We then propose a resolution based on an examination of the properties of quantum gravity under circumstances that give rise to a classical singularity. We show that the gravitational wavefunction vanishes as one gets close to the classical singularity. This results in a future boundary condition inside the black hole that allows for quantum information to be recovered in the evaporation process.

上午10:21 | | | gr-qc updates on arXiv.org |

Authors: J. Baeza-Ballesteros, A. Donini, S. Nadal-Gisbert

In a previous work (arXiv:1609.05654v2), an experimental setup aiming at the measurement of deviations from the Newtonian $1/r^2$ distance dependence of gravitational interactions was proposed. The theoretical idea behind this setup was to study the trajectories of a “Satellite” with a mass $m_{\rm S} \sim {\cal O}(10^{-9})$ $\mathrm{g}$ around a “Planet” with mass $m_{\rm P} \in [10^{-7},10^{-5} ]$ $\mathrm{g}$, looking for precession of the orbit. The observation of such feature induced by gravitational interactions would be an unambiguous indication of a gravitational potential with terms different from $1/r$ and, thus, a powerful tool to detect deviations from Newton’s $1/r^2$ law. In this paper we optimize the proposed setup in order to achieve maximal sensitivity to look for {\em Beyond-Newtonian} corrections. We study in detail possible background sources that could induce precession and quantify their impact on the achievable sensitivity. We conclude that a dynamical measurement of deviations from newtonianity can test Yukawa-like corrections to the $1/r$ potential with strength as low as $\alpha \sim 10^{-2}$ for distances as small as $\lambda \sim 10 \, \mu\mathrm{m}$.

Truthlikeness for probabilistic laws

2021年6月18日 星期五 上午8:00 | | | Latest Results for Synthese |

**Abstract**

Truthlikeness is a property of a theory or a proposition that represents its *closeness to the truth*. We start by summarizing Niiniluoto’s (Truthlikeness, Reidel, Dordrecht, 1987) proposal of truthlikeness for deterministic laws (DL), which defines truthlikeness as a function of accuracy, and García-Lapeña’s (Br J Philos Sci, Forthcoming, 2021) expanded version, which defines truthlikeness for DL as a function of two factors, accuracy and nomicity. Then, we move to develop an appropriate definition of truthlikeness for probabilistic laws (PL) based on Niiniluoto’s (Truthlikeness, Reidel, Dordrecht, 1987) suggestion to use the Kullback–Leibler divergence to define the distance between a probability law \(X\) and the true probability law \(T\) . We argue that the Kullback–Leibler divergence seems to be the best of the available probability distances to measure accuracy between PL. However, as in the case of DL, we argue that accuracy represents a necessary but not sufficient condition, as two PL may be equally accurate and still one may imply more true or truthlike consequences, behaviours or true facts about the system than the other. The final proposal defines truthlikeness for PL as a function of two factors, p-accuracy and p-nomicity, in intimate connexion with García-Lapeña’s proposal for DL.

Introduction: Individuality, Distinguishability, and (Non‑)Entanglement

2021年6月18日 星期五 上午7:13 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Friebe, Cord and Salimkhani, Kian and Wachter, Tina (2021) Introduction: Individuality, Distinguishability, and (Non‑)Entanglement. Journal for General Philosophy of Science. ISSN 0925-4560

Humeanism in Light of Quantum Gravity

2021年6月18日 星期五 上午7:12 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Cinti, Enrico and Sanchioni, Marco (2021) Humeanism in Light of Quantum Gravity. [Preprint]

Does Neuroplasticity Support the Hypothesis of Multiple Realizability?

2021年6月12日 星期六 下午4:14 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Maimon, Amber and Hemmo, Meir (2020) Does Neuroplasticity Support the Hypothesis of Multiple Realizability? [Preprint]

]]>上午9:49 | | | Nuriya Nurgalieva, Renato Renner | | | quant-ph updates on arXiv.org |

Quantum mechanics is one of our most successful physical theories; its predictions agree with experimental observations to an extremely high accuracy. However, the bare formalism of quantum theory does not provide straightforward answers to seemingly simple questions: for example, how should one model systems that include agents who are themselves using quantum theory? These foundational questions may be investigated with a theorist’s tool — the thought experiment. Its purpose is to turn debates about the interpretation of quantum theory into actual physics questions. In this article, we give a state-of-the-art overview on quantum thought experiments involving observers, from the basic Wigner’s friend to the recent Frauchiger-Renner setup, clarifying their interpretational significance and responding to objections and criticism on the way.

上午9:49 | | | Giulio Gasbarri, Alessio Belenchia, Matteo Carlesso, Sandro Donadi, Angelo Bassi, Rainer Kaltenbaek, Mauro Paternostro, Hendrik Ulbricht | | | quant-ph updates on arXiv.org |

Quantum technologies are opening novel avenues for applied and fundamental science at an impressive pace. In this perspective article, we focus on the promises coming from the combination of quantum technologies and space science to test the very foundations of quantum physics and, possibly, new physics. In particular, we survey the field of mesoscopic superpositions of nanoparticles and the potential of interferometric and non-interferometric experiments in space for the investigation of the superposition principle of quantum mechanics and the quantum-to-classical transition. We delve into the possibilities offered by the state-of-the-art of nanoparticle physics projected in the space environment and discuss the numerous challenges, and the corresponding potential advancements, that the space environment presents. In doing this, we also offer an ab-initio estimate of the potential of space-based interferometry with some of the largest systems ever considered and show that there is room for tests of quantum mechanics at an unprecedented level of detail.

Bohmian Zitterbewegung. (arXiv:2106.05827v1 [quant-ph])

上午9:49 | | | Giuseppe Raguni | | | quant-ph updates on arXiv.org |

A new bohmian quantum-relativistic model, in which arises a generalization of the classic Zitterbewegung discovered by Schr\”odinger, is proposed. It is obtained by introducing a new independent time parameter, whose relative motions are not directly observable but cause the uncertainties of the quantum observables. Unlike Bohm’s original theory, the quantum potential does not affect the observable motion, as for a normal external potential, but it only determines that one relative to the new time variable, of which the Zitterbewegung of a free particle is an example. The model also involves a relativistic revision of the uncertainty principle for particles with non-zero rest mass.

上午9:49 | | | Ricardo Gallego Torromé | | | quant-ph updates on arXiv.org |

Quantum systems are viewed as emergent systems from the fundamental degrees of freedom. The laws and rules of quantum mechanics are understood as an effective description, valid for the emergent systems and specially useful to handle probabilistic predictions of observables. After introducing the geometric theory of Hamilton-Randers spaces and reformulating it using Hilbert space theory, a Hilbert space structure is constructed from the Hilbert space formulation of the underlying Hamilton-Randers model and associated with the space of wave functions of quantum mechanical systems. We can prove the emergence of the Born rule from ergodic considerations. A geometric mechanism for a natural spontaneous collapse of the quantum states based on the concentration of measure phenomena as it appears in metric geometry is discussed.We show the existence of stable vacua states for the quantized matter Hamiltonian. Another consequence of the concentration of measure is the emergence of a weak equivalence principle for one of the dynamics of the fundamental degrees of freedom. We suggest that the reduction of the quantum state is driven by a gravitational type interaction.

Such interaction appears only in the dynamical domain when localization of quantum observables happens, it must be a classical interaction. We discuss the double slit experiment in the context of the framework proposed, the interference phenomena associated with a quantum system in an external gravitational potential, a mechanism explaining non-quantum locality and also provide an argument in favour of an emergent interpretation of every macroscopic time parameter. Entanglement is partially described in the context of Hamilton-Randers theory and how naturally Bell’s inequalities should be violated.

上午9:49 | | | Thomas D. Galley, Flaminia Giacomini, John H. Selby | | | quant-ph updates on arXiv.org |

Recently, table-top experiments involving massive quantum systems have been proposed to test the interface of quantum theory and gravity. In particular, the crucial point of the debate is whether it is possible to conclude anything on the quantum nature of the gravitational field, provided that two quantum systems become entangled due to solely the gravitational interaction. Typically, this question has been addressed by assuming an underlying physical theory to describe the gravitational interaction, but no systematic approach to characterise the set of possible gravitational theories which are compatible with the observation of entanglement has been proposed. Here, we introduce the framework of Generalised Probabilistic Theories (GPTs) to the study of the nature of the gravitational field. This framework has the advantage that it only relies on the set of operationally accessible states, transformations, and measurements, without presupposing an underlying theory. Hence, it provides a framework to systematically study all theories compatible with the detection of entanglement generated via the gravitational interaction between two non-classical systems. Assuming that such entanglement is observed we prove a no-go theorem stating that the following statements are incompatible: i) the two non-classical systems are independent subsystems, ii) the gravitational field is a physical degree of freedom which mediates the interaction and iii) the gravitational field is classical. Moreover we argue that conditions i) and ii) should be met, and hence that the gravitational field is non-classical. Non-classicality does not imply that the gravitational field is quantum, and to illustrate this we provide examples of non-classical and non-quantum theories which are logically consistent with the other conditions.

Causality and gravity. (arXiv:2106.05912v1 [hep-th])

上午9:49 | | | gr-qc updates on arXiv.org |

Authors: John F. Donoghue, Gabriel Menezes

We show how uncertainty in the causal structure of field theory is essentially inevitable when one includes quantum gravity. This includes the fact that lightcones are ill-defined in such a theory – independent of the UV completion of the theory. We include details of the causality uncertainty which arises in theories of quadratic gravity.

Testing the black-hole area law with GW150914. (arXiv:2012.04486v2 [gr-qc] UPDATED)

上午9:49 | | | gr-qc updates on arXiv.org |

Authors: Maximiliano Isi, Will M. Farr, Matthew Giesler, Mark A. Scheel, Saul A. Teukolsky

We present observational confirmation of Hawking’s black-hole area theorem based on data from GW150914, finding agreement with the prediction with 97% (95%) probability when we model the ringdown including (excluding) overtones of the quadrupolar mode. We obtain this result from a new time-domain analysis of the pre- and postmerger data. We also confirm that the inspiral and ringdown portions of the signal are consistent with the same remnant mass and spin, in agreement with general relativity.

A closer glance at black hole pair creation. (arXiv:2103.05782v2 [hep-th] UPDATED)

上午9:49 | | | gr-qc updates on arXiv.org |

Authors: Anrés Anabalón, Sasha Brenner, Gaston Giribet, Luciano Montecchio

We consider accelerated black hole horizons with and without defects. These horizons appear in the $C$-metric solution to Einstein equations and in its generalization to the case where external fields are present. These solutions realize a variety of physical processes, from the decay of a cosmic string by a black hole pair nucleation to the creation of a black hole pair by an external electromagnetic field. Here, we show that such geometries exhibit an infinite set of symmetries in their near horizon region, generalizing in this way previous results for smooth isolated horizons. By considering the limit close to both the black hole and the acceleration horizons, we show that a sensible set of asymptotic boundary conditions gets preserved by supertranslation and superrotation transformations. By acting on the geometry with such transformations, we derive the superrotated, supertranslated version of the $C$-metric and compute the associated conserved charges.

Black hole remnants are not too fast to be dark matter. (arXiv:2105.01627v2 [gr-qc] UPDATED)

上午9:49 | | | gr-qc updates on arXiv.org |

Authors: Benjamin V. Lehmann, Stefano Profumo

We comment on recent claims that recoil in the final stages of Hawking evaporation gives black hole remnants large velocities, rendering them inviable as a dark matter candidate. We point out that due to cosmic expansion, such large velocities at the final stages of evaporation are not in tension with the cold dark matter paradigm so long as they are attained at sufficiently early times. In particular, the predicted recoil velocities are robustly compatible with observations if the remnants form before the epoch of big bang nucleosynthesis, a requirement which is already imposed by the physics of nucleosynthesis itself.

Machines will think: structure and interpretation of Alan Turing’s imitation game

上午7:30 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Gonçalves, Bernardo (2021) Machines will think: structure and interpretation of Alan Turing’s imitation game. The Digital Library of Theses and Dissertations of the University of São Paulo. pp. 1-291.

Relativistic Bell Test within Quantum Reference Frames

2021年6月11日 星期五 下午6:00 | | | Lucas F. Streiter, Flaminia Giacomini, and Časlav Brukner | | | PRL: General Physics: Statistical and Quantum Mechanics, Quantum Information, etc. |

Author(s): Lucas F. Streiter, Flaminia Giacomini, and Časlav Brukner

A still widely debated question in the field of relativistic quantum information is whether entanglement and the degree of violation of Bell’s inequalities for massive relativistic particles are frame independent or not. At the core of this question is the effect that spin gets entangled with the mo…

[Phys. Rev. Lett. 126, 230403] Published Fri Jun 11, 2021

Energy Requirements Undermine Substrate Independence and Mind-Body Functionalism

2021年6月10日 星期四 下午3:43 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Thagard, Paul (2021) Energy Requirements Undermine Substrate Independence and Mind-Body Functionalism. [Preprint]

2021年6月9日 星期三 上午8:00 | | | Romain Fleury | | | Nature Physics – Issue – nature.com science feeds |

Nature Physics, Published online: 09 June 2021; doi:10.1038/s41567-021-01281-5

Introducing non-local effects to metamaterials increases the complexity of their dispersion relation, which allows carefully designed elastic structures to mimic the peculiar roton behaviour of correlated quantum superfluids.

Absolute Space as a Necessary Idea: Reading Kant’s Phenomenology through Perspectival Lenses

2021年6月8日 星期二 上午6:01 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Massimi, Michela (2021) Absolute Space as a Necessary Idea: Reading Kant’s Phenomenology through Perspectival Lenses. [Preprint]

“Reverse Engineering” the de Broglie Wave

2021年6月8日 星期二 上午5:57 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Shanahan, Daniel “Reverse Engineering” the de Broglie Wave. UNSPECIFIED.

A response to the Mucino-Okon-Sudarsky’s Assessment of Relational Quantum Mechanics

2021年6月8日 星期二 上午5:54 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

ROVELLI, Carlo (2021) A response to the Mucino-Okon-Sudarsky’s Assessment of Relational Quantum Mechanics. [Preprint]

]]>下午5:25 | | | Alan Barr | | | quant-ph updates on arXiv.org |

Higgs boson decays produce pairs of W bosons in a maximally entangled state, the spins of which can be expected to violate Bell inequalities. We show that the spin density matrix of the $W^\pm$ pair may be reconstructed experimentally from the directions of the emitted leptons, and from it the expectation values of various Bell operators determined. Simulations of $H \rightarrow W^+W^-$ indicate that violation of the CHSH inequality is unlikely to be measurable, however the CGLMP inequality is near-maximally violated, with large statistical significances which might be observable even with existing LHC data.

下午5:25 | | | Tomasz Maciążek, Uzy Smilansky | | | quant-ph updates on arXiv.org |

The spectrum of a real and symmetric $N\times N$ matrix determines the matrix up to unitary equivalence. More spectral data is needed together with some sign indicators to remove the unitary ambiguities. This work specifies the spectral and sign information required for a unique reconstruction of general matrices. More specifically, the spectral information consists of the spectra of the $N$ nested main minors of the original matrix of the sizes $1,2,\dots,N$. However, due to the complicated nature of the required sign data, improvements are needed in order to make the reconstruction procedure feasible. With this in mind, we restrict our attention to banded matrices where the amount of spectral data exceeds the number of the unknown matrix entries. It is shown that one can take advantage of this redundancy to guarantee unique reconstruction of {\it generic} matrices. The space of non-generic matrices is defined either via a set of polynomial equations or via a set of equations involving eigenvectors. Thus, the space of non-generic matrices has a positive co-dimension as a subspace of the space of all matrices. It is shown that one can optimize the ratio between redundancy and genericity by using the freedom of choice of the spectral information input. We demonstrate our constructions in detail for pentadiagonal matrices.

Background Independence and Quantum Causal Structure. (arXiv:2106.01038v2 [quant-ph] UPDATED)

下午5:25 | | | Lachlan Parker, Fabio Costa | | | quant-ph updates on arXiv.org |

One of the key ways in which quantum mechanics differs from relativity is that it requires a fixed background reference frame for spacetime. In fact, this appears to be one of the main conceptual obstacles to uniting the two theories. Additionally, a combination of the two theories is expected to yield non-classical, or “indefinite”, causal structures. In this paper, we present a background-independent formulation of the process matrix formalism – a form of quantum mechanics that allows for indefinite causal structure – while retaining operationally well-defined measurement statistics. We do this by postulating an arbitrary probability distribution of measurement outcomes across discrete “chunks” of spacetime, which we think of as physical laboratories, and then requiring that this distribution be invariant under any permutation of laboratories. We find (a) that one still obtains nontrivial, indefinite causal structures with background independence, (b) that we lose the idea of local operations in distinct laboratories, but can recover it by encoding a reference frame into the physical states of our system, and (c) that permutation invariance imposes surprising symmetry constraints that, although formally similar to a superselection rule, cannot be interpreted as such.

下午5:25 | | | physics.hist-ph updates on arXiv.org |

Authors: Adel Alameh

The law of centripetal force governing the motion of celestial bodies in eccentric conic sections, has been established and thoroughly investigated by Sir Isaac Newton in his Principia Mathematica. Yet its profound implications on the understanding of such motions is still evolving. In a paper to the royal academy of science, Sir Willian Hamilton demonstrated that this law underlies the circular character of hodographs for Kepler orbits. A fact which was the object of ulterior research and exploration by Richard Feynman and many other authors [1]. In effect, a minute examination of the geometry of elliptic trajectories, reveals interesting geometric properties and relations, altogether, combined with the law of conservation of angular momentum lead eventually, and without any recourse to dealing with differential equations, to the appearance of the equation of the trajectory and to the derivation of the equation of its corresponding hodograph. On this respect, and for the sake of founding the approach on solid basis, I devised two mathematical theorems; one concerning the existence of geometric means, and the other is related to establishing the parametric equation of an off-center circle, altogether compounded with other simple arguments ultimately give rise to the inverse square law of force that governs the motion of bodies in elliptic trajectories, as well as to the equation of their inherent circular hodographs.

下午5:25 | | | physics.hist-ph updates on arXiv.org |

Authors: Oliver Davis Johns

Momentum and energy conservation require electromagnetic field momentum and energy to be treated as physically real, even in static fields. This motivates the conjecture that field momentum might be due to the flow of a relativistic mass density (defined as energy density divided by the square of the speed of light). This article investigates the velocity of such a mass flow and finds a conflict between two different definitions of it, both of which originally seem plausible if the flow is to be taken as real. This investigation is careful to respect the transformation rules of special relativity throughout. The paper demonstrates that the consensus definition of the flow velocity of electromagnetic energy is inconsistent with the transformation rules of special relativity, and hence is incorrect. A replacement flow velocity is derived which is completely consistent with those transformation rules. The conclusion is that these conflicting definitions of flow velocity cannot be resolved in a way that is consistent with special relativity and also allows electromagnetic field momentum density to be the result of relativistic mass flow. Though real, field momentum density cannot be explained as the flow of a relativistic mass density. As a byproduct of the study, it is also shown that there is a comoving system in which the electromagnetic energy-momentum tensor is reduced to a simple diagonal form, with two of its diagonal elements equal to the energy density and the other two diagonal elements equal to plus and minus a single parameter derived from the electromagnetic field values, a result that places constraints on possible fluid models of electromagnetism.

Exploring black holes as particle accelerators in realistic scenarios. (arXiv:2106.01385v1 [gr-qc])

下午5:25 | | | gr-qc updates on arXiv.org |

Authors: Stefano Liberati, Christian Pfeifer, José Javier Relancio

The possibility that rotating black holes could be natural particle accelerators has been subject of intense debate. While it appears that for extremal Kerr black holes arbitrarily high center of mass energies could be achieved, several works pointed out that both theoretical as well as astrophysical arguments would severely dampen the attainable energies. In this work we study particle collisions near Kerr–Newman black holes, by reviewing and extending previously proposed scenarios. Most importantly, we implement the hoop conjecture for all cases and we discuss the astrophysical relevance of these collisional Penrose processes. The outcome of this investigation is that scenarios involving near-horizon target particles are in principle able to attain, sub-Planckian, but still ultra high, center of mass energies of the order of $10^{21}-10^{23}$ eV. Thus, these target particle collisional Penrose processes could contribute to the observed spectrum of ultra high-energy cosmic rays, even if the hoop conjecture is taken into account, and as such deserve further scrutiny in realistic settings.

Hearts of Darkness: the inside out probing of black holes. (arXiv:2106.01530v1 [gr-qc])

下午5:25 | | | gr-qc updates on arXiv.org |

Authors: Raúl Carballo-Rubio, Francesco Di Filippo, Stefano Liberati

Classical black holes shield us from the singularities that inevitably appear in general relativity. Being singularity regularization one of the main landmarks for a successful theory of quantum gravity, quantum black holes are not obliged to hide their inner core from the outside world. Notwithstanding the aforesaid, it is often implicitly assumed that quantum gravity effects must remain confined to black hole interiors. In this essay we argue in the opposite direction, discussing theoretical evidence for the existence of strong correlations between the physics inside and outside non-singular black holes. We conclude that astronomical tests of the surroundings of black holes can provide invaluable information about their so-far unexplored interiors.

下午5:25 | | | gr-qc updates on arXiv.org |

Authors: Karim Mosani, Dipanjan Dey, Pankaj S. Joshi, Gauranga C. Samanta, Harikrishnan Menon, Vaishnavi D. Patel

We argue that the global causal structure of the singularity is not a purely geometric property but also depends on the collapsing matter-field leading to its formation. To show this, we investigate the global visibility of the end state of a spherically symmetric marginally bound Lemaitre-Tolman-Bondi collapsing cloud (which is well studied in general relativity) in the framework of modified gravity having the generalized Lagrangian $R+\alpha R^2$ in the Einstein-Hilbert action. Here $R$ is the Ricci scalar, and $\alpha>0$ is a constant. As an example, we depict that for the same LTB metric governing the spacetime formed due to two different matter-fields, i.e., dust in general relativity and imperfect viscous fluid in $f(R)$ gravity, the singularity is locally visible in the former case, and globally visible in the latter case.

Intuition in Einsteinian Physics. (arXiv:2106.01820v1 [gr-qc])

下午5:25 | | | gr-qc updates on arXiv.org |

Authors: Bernard F. Schutz

This chapter sets the stage for the rest of the book by exploring the role of intuition as a tool to deepen understanding in Einsteinian physics. Drawing on examples from the history of general relativity, we argue that the development of physical intuition is a crucial goal in physics education in parallel with any mathematical development of a physics subject.

This chapter is for readers who wish to learn how expert physicists think conceptually about their subjects to understand them plus readers who wish to see how we can introduce Einsteinian physics to students by developing their intuition as well as teaching them the mathematics.

Information recovery from evaporating black holes. (arXiv:2105.00198v2 [gr-qc] UPDATED)

下午5:25 | | | gr-qc updates on arXiv.org |

Authors: Samuel L. Braunstein, Saurya Das, Zhi-Wei Wang

We show that the apparent horizon and the region near $r=0$ of an evaporating charged, rotating black hole are timelike. It then follows that for black holes in nature, which invariably have some rotation, have a channel, via which classical or quantum information can escape to the outside, while the black hole shrinks in size. We discuss implications for the information loss problem.

Quantum imprints of gravitational shockwaves. (arXiv:2105.09337v2 [hep-th] UPDATED)

下午5:25 | | | gr-qc updates on arXiv.org |

Authors: Finnian Gray, David Kubiznak, Taillte May, Sydney Timmerman, Erickson Tjoa

Gravitational shockwaves are simple exact solutions of Einstein equations representing the fields of ultrarelativistic sources and idealized gravitational waves (shocks). Historically, much work has focused on shockwaves in the context of possible black hole formation in high energy particle collisions, yet they remain at the forefront of research even today. Representing hard modes in the bulk, shocks give rise to the gravitational memory effect at the classical level and implant supertranslation (BMS) hair onto a classical spacetime at the quantum level. The aim of this paper is to further our understanding of the `information content’ of such supertranslations. Namely, we show that, contrary to the several claims in the literature, a gravitational shockwave does leave a quantum imprint on the vacuum state of a test quantum field and that this imprint is accessible to local observers carrying Unruh–DeWitt (UDW) detectors in this spacetime.

下午5:25 | | | gr-qc updates on arXiv.org |

Authors: Narayan Khadka, Orlando Luongo, Marco Muccino, Bharat Ratra

We study eight different gamma-ray burst (GRB) data sets to examine whether current GRB measurements — that probe a largely unexplored part of cosmological redshift ($z$) space — can be used to reliably constrain cosmological model parameters. We use three Amati-correlation samples and five Combo-correlation samples to simultaneously derive correlation and cosmological model parameter constraints. The intrinsic dispersion of each GRB data set is taken as a goodness measurement. We examine the consistency between the cosmological bounds from GRBs with those determined from better-established cosmological probes, such as baryonic acoustic oscillation (BAO) and Hubble parameter $H(z)$ measurements. We use the Markov chain Monte Carlo method implemented in \textsc{MontePython} to find best-fit correlation and cosmological parameters, in six different cosmological models, for the eight GRB samples, alone or in conjunction with BAO and $H(z)$ data. For the Amati correlation case, we compile a data set of 118 bursts, the A118 sample, which is the largest — about half of the total Amati-correlation GRBs — current collection of GRBs suitable for constraining cosmological parameters. This updated GRB compilation has the smallest intrinsic dispersion of the three Amati-correlation GRB data sets we examined. We are unable to define a collection of reliable bursts for current Combo-correlation GRB data. Cosmological constraints determined from the A118 sample are consistent with — but significantly weaker than — those from BAO and $H(z)$ data. They also are consistent with the spatially-flat $\Lambda$CDM model as well as with dynamical dark energy models and non-spatially-flat models. Since GRBs probe a largely unexplored region of $z$, it is well worth acquiring more and better-quality burst data which will give a more definitive answer to the question of the title.

Information Causality without Concatenation

2021年6月4日 星期五 下午6:00 | | | Nikolai Miklin and Marcin Pawłowski | | | PRL: General Physics: Statistical and Quantum Mechanics, Quantum Information, etc. |

Author(s): Nikolai Miklin and Marcin Pawłowski

Information causality is a physical principle which states that the amount of randomly accessible data over a classical communication channel cannot exceed its capacity, even if the sender and the receiver have access to a source of nonlocal correlations. This principle can be used to bound the nonl…

[Phys. Rev. Lett. 126, 220403] Published Fri Jun 04, 2021

2021年6月4日 星期五 上午8:00 | | | Latest Results for Synthese |

**Abstract**

Say that metaphysical indeterminacy occurs just when there is a fact such that neither it nor its negation obtains. The aim of this work is to shed light on the issue of whether orthodox quantum mechanics provides any evidence of metaphysical indeterminacy by discussing the logical, semantic, and broadly methodological presuppositions of the debate. I argue that the dispute amounts to a verbal disagreement between classical and quantum logicians, given Eli Hirsch’s account of substantivity; but that it need not be so if Ted Sider’s naturalness-based account of substantivity is adopted instead. Given the latter approach, can anything be said in order to tip the balance of the dispute either way? Some *prima facie* reasonable constraints on naturalness entail that the classicist is right, and the quantum world is therefore determinate. Nevertheless, there are reasons for weakening those constraints, to the effect that the dispute remains very much open. Finally, I discuss alternative accounts of metaphysical indeterminacy, and argue that they are unsuitable for framing the quantum indeterminacy debate.

Recovering General Relativity from a Planck scale discrete theory of quantum gravity

2021年6月4日 星期五 上午2:20 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Butterfield, Jeremy and Dowker, Fay (2021) Recovering General Relativity from a Planck scale discrete theory of quantum gravity. [Preprint]

2021年6月4日 星期五 上午2:15 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Lampert, Timm (2021) Newton’s experimental proofs. THEORIA. An International Journal for Theory, History and Foundations of Science, 36 (2). pp. 261-283. ISSN 2171-679X

Reflections off a relativistic mirror

2021年6月3日 星期四 上午8:00 | | | Laszlo Veisz | | | Nature Physics – Issue – nature.com science feeds |

Nature Physics, Published online: 03 June 2021; doi:10.1038/s41567-021-01259-3

High-order harmonics of laser pulses yield spectral components with shorter wavelength and duration and tighter focus than the original pulse. Precise spatiotemporal characterization of this radiation from a relativistic plasma mirror is relevant for ultrafast science.

John Bell on ‘Subject and Object’: an Exchange

2021年6月2日 星期三 下午3:45 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Halvorson, Hans and Butterfield, Jeremy (2021) John Bell on ‘Subject and Object’: an Exchange. [Preprint]

The Strong Arm of the Law – A Unified Account of Necessary and Contingent Laws of Nature

2021年6月2日 星期三 下午3:44 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Hirèche, Salim and Linnemann, Niels and Michels, Robert and Vogt, Lisa (2021) The Strong Arm of the Law – A Unified Account of Necessary and Contingent Laws of Nature. [Preprint]

A Dialogue on the Ethics of Science: Henri Poincaré and Pope Francis

2021年6月2日 星期三 下午3:43 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

Danne, Nicholas (2021) A Dialogue on the Ethics of Science: Henri Poincaré and Pope Francis. [Preprint]

Bilocal Bell Inequalities Violated by the Quantum Elegant Joint Measurement

2021年6月1日 星期二 下午6:00 | | | Armin Tavakoli, Nicolas Gisin, and Cyril Branciard | | | PRL: General Physics: Statistical and Quantum Mechanics, Quantum Information, etc. |

Author(s): Armin Tavakoli, Nicolas Gisin, and Cyril Branciard

Network Bell experiments give rise to a form of quantum nonlocality that conceptually goes beyond Bell’s theorem. We investigate here the simplest network, known as the bilocality scenario. We depart from the typical use of the Bell state measurement in the network central node and instead introduce…

[Phys. Rev. Lett. 126, 220401] Published Tue Jun 01, 2021

Theoretical equivalence and duality

2021年6月1日 星期二 上午8:00 | | | Latest Results for Synthese |

**Abstract**

Theoretical equivalence and duality are two closely related notions: but their interconnection has so far not been well understood. In this paper I explicate the contribution of a recent schema for duality to discussions of theoretical equivalence. I argue that duality suggests a construal of theoretical equivalence in the physical sciences. The construal is in terms of the isomorphism of models, as defined by the schema. This construal gives interpretative constraints that should be useful for discussions of theoretical equivalence more generally. I illustrate the construal in various formulations of Maxwell’s electromagnetic theory.

2021年6月1日 星期二 上午8:00 | | | Latest Results for Synthese |

**Abstract**

I defend the following argument in this paper. Premise 1: Laws of nature are intrinsic to the universe. Premise 2: Humeanism maintains that laws of nature are extrinsic to the universe. Conclusion: Humeanism is false. This argument is inspired by Hawthorne’s (Noûs 38(2):351–358, 2004) argument in “Humeans are out of their Minds”. My argument differs from his; Hawthorne focuses on Humean views of causation and how they interact with judgments about consciousness. He thinks Humeans are forced to treat certain mental properties (insofar as they involve causal features) as extrinsic to conscious minds. I do not discuss causation or consciousness here. I focus on Humean accounts of laws. I argue that Humean laws are extrinsic to the entire universe. As such, Humeans are not just out of their minds; they are out of this world. I aim to show that premises 1 and 2 are well-supported and that denying either of them comes at a cost. Nevertheless, some Humeans may prefer to reject 1 or 2 rather than give up Humeanism. Even if the Humean takes one of these routes, the argument above has philosophical import: it shows that Humeanism involves surprising commitments.

Are non-accidental regularities a cosmic coincidence? Revisiting a central threat to Humean laws

2021年6月1日 星期二 上午8:00 | | | Latest Results for Synthese |

**Abstract**

If the laws of nature are as the Humean believes, it is an unexplained cosmic coincidence that the actual Humean mosaic is as extremely regular as it is. This is a strong and well-known objection to the Humean account of laws. Yet, as reasonable as this objection may seem, it is nowadays sometimes dismissed. The reason: its unjustified implicit assignment of equiprobability to each possible Humean mosaic; that is, its assumption of the principle of indifference, which has been attacked on many grounds ever since it was first proposed. In place of equiprobability, recent formal models represent the doxastic state of total ignorance as suspension of judgment. In this paper I revisit the cosmic coincidence objection to Humean laws by assessing which doxastic state we should endorse. By focusing on specific features of our scenario I conclude that suspending judgment results in an unnecessarily weak doxastic state. First, I point out that recent literature in epistemology has provided independent justifications of the principle of indifference. Second, given that the argument is framed within a Humean metaphysics, it turns out that we are warranted to appeal to these justifications and assign a uniform and additive credence distribution among Humean mosaics. This leads us to conclude that, contrary to widespread opinion, we should not dismiss the cosmic coincidence objection to the Humean account of laws.

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