2019年10月11日 星期五 下午8:32 | | | physics.hist-ph updates on arXiv.org |

Authors: Mordehai Milgrom

MOND is a paradigm that contends to account for the mass discrepancies in the Universe without invoking `dark’ components, such as `dark matter’ and `dark energy’. It does so by supplanting Newtonian dynamics and General Relativity, departing from them at very low accelerations. Having in mind historians and philosophers of science, as well as physicists and astronomers, I describe in this review the main aspects of MOND — its statement, its basic tenets, its main predictions, and the tests of these predictions — contrasting it with the dark-matter paradigm. I then discuss possible wider ramifications of MOND, for example the potential significance of the MOND constant, $a_0$, and its possible implications for the roots of MOND in cosmology. Along the way I point to parallels with several historical instances of nascent paradigms. In particular, with the emergence of the Copernican world picture, that of quantum physics, and that of relativity. I point to analogies between these paradigms as regards their initial advent, their development, their schematic structure, and their ramifications. For example, the interplay between theories and their corollary laws, and the centrality of a new constant with converging values as deduced from seemingly unrelated manifestations of these laws. I parallel the struggle of the new with the old paradigms, and the appearance of hybrid paradigms at such times of struggle. I also try to identify in the history of those established paradigms a stage that can be likened to that of MOND today.

2019年10月11日 星期五 下午8:32 | | | physics.hist-ph updates on arXiv.org |

Authors: Antonio Vassallo

The paper discusses from a metaphysical standpoint the nature of the dependence relation underpinning the talk of mutual action between material and spatiotemporal structures in general relativity. It is shown that the standard analyses of dependence in terms of causation or grounding are ill-suited for the general relativistic context. Instead, a non-standard analytical framework in terms of structural equation modeling is exploited, which leads to the conclusion that the kind of dependence encoded in the Einstein field equations is a novel one.

2019年10月11日 星期五 下午8:32 | | | physics.hist-ph updates on arXiv.org |

Authors: S.Deser

To celebrate Roman Jackiw’s 80th birthday, herewith some comments on gravity and gauge theory models in D=3, the chief focus of many of our joint efforts.

2019年10月11日 星期五 下午8:32 | | | quant-ph updates on arXiv.org |

Authors: Huiping Zhan, Gaoxiang Li, Huatang Tan

In this paper, we propose a feasible scheme for generating the Schr\”{o}dinger cat states of a macroscopic mechanical resonator in pulsed cavity optomechanics. Starting with cooling the mechanical oscillator to its ground state, a red and a blue pulses with different powers are simultaneously employed to drive the cavity to achieve squeezed mechanical states. Subsequently, a second red pulse is utilized to generate the macroscopic mechanical quantum superpositions, conditioned on the detection of cavity output photons. Finally, after being stored in the resonator for a period of time, the mechanical state is mapped, with a third red pulse, to the cavity output field used for state verification. Our approach is generic and can also be used to produce other kinds of non-Gaussian mechanical states, like optical-catalysis nonclassical states.

2019年10月11日 星期五 下午8:32 | | | quant-ph updates on arXiv.org |

Authors: Yurii V. Brezhnev

Clarifying the nature of the quantum state $|\Psi\rangle$ is at the root of the problems with insight into (counterintuitive) quantum postulates. We provide a direct-and math-axiom free-empirical derivation of this object as an element of a vector space. Establishing the linearity of this structure-quantum superposition-is based on a set-theoretic creation of ensemble formations and invokes the following three principia: $(\textsf{I})$ quantum statics, $(\textsf{II})$ doctrine of a number in the physical theory, and $(\textsf{III})$ mathematization of matching the two observations with each other; quantum invariance.

All of the constructs rest upon a formalization of the minimal experimental entity: observed micro-event, detector click. This is sufficient for producing the $\mathbb C$-numbers, axioms of linear vector space (superposition principle), statistical mixtures of states, eigenstates and their spectra, and non-commutativity of observables. No use is required of the concept of time. As a result, the foundations of theory are liberated to a significant extent from the issues associated with physical interpretations, philosophical exegeses, and mathematical reconstruction of the entire quantum edifice.

2019年10月11日 星期五 下午8:32 | | | quant-ph updates on arXiv.org |

Authors: Yurii V. Brezhnev

We deduce the Born rule. No use is required of quantum postulates. One exploits only rudimentary quantum mathematics–a linear, not Hilbert’, vector space–and empirical notion of the statistical length of a state. Its statistical nature comes from the experimental detector-clicks being formalized into the abstract quantum micro-events. We also comment on that it is not only that the use has not been made of some quantum axioms when deriving the rule but, in a sense, their invoking would be inconsistent.

2019年10月11日 星期五 下午8:32 | | | gr-qc updates on arXiv.org |

Authors: Vitor Cardoso

Because of the very definition of black holes — no light escapes them and falling objects get infinitely faint when approaching — it is impossible to ever prove that they exist. However, electromagnetic and gravitational-wave observatories have now `seen’ black holes. Datasets from these observations, released in 2019 and late 2018, give important hints about the environment, origin and growth of black holes.

2019年10月11日 星期五 下午8:32 | | | gr-qc updates on arXiv.org |

Authors: Andrea Dapor, Klaus Liegener, Tomasz Pawłowski

We reexamine a set of existing procedures aimed at recovering the effective description of the dynamics of LQG in the context of cosmological solutions. In particular, the studies of those methods, to which the choice of cuboidal graphs and graph-preserving Hamiltonian is central, result in the formulation of a set of no-go statements, severely limiting the possibility of recovering a physically consistent effective dynamics this way.

2019年10月11日 星期五 下午8:32 | | | gr-qc updates on arXiv.org |

Authors: Steven Duplij (University of Münster)

Supergravity is a remarkable theory combining supersymmetry and general relativity. While the theory has many developers from across the globe, we wish to address the question who were the real originators of this fantastic idea.

2019年10月10日 星期四 下午6:00 | | | Robert Pisarczyk, Zhikuan Zhao, Yingkai Ouyang, Vlatko Vedral, and Joseph F. Fitzsimons | | | PRL: General Physics: Statistical and Quantum Mechanics, Quantum Information, etc. |

Author(s): Robert Pisarczyk, Zhikuan Zhao, Yingkai Ouyang, Vlatko Vedral, and Joseph F. Fitzsimons

The capacity of a channel is known to be equivalent to the highest rate at which it can generate entanglement. Analogous to entanglement, the notion of a causality measure characterizes the temporal aspect of quantum correlations. Despite holding an equally fundamental role in physics, temporal quan…

[Phys. Rev. Lett. 123, 150502] Published Thu Oct 10, 2019

2019年10月10日 星期四 下午1:52 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

2019年10月10日 星期四 下午1:43 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

2019年10月10日 星期四 上午8:00 | | | Latest Results for Foundations of Physics |

### Abstract

The relationship whereby one physical theory encompasses the domain of empirical validity of another is widely known as “reduction.” Elsewhere I have argued that one influential methodology for showing that one physical theory reduces to another, associated with the so-called “Bronstein cube” of theories, rests on an oversimplified and excessively vague characterization of the mathematical relationship between theories that typically underpins reduction. I offer what I claim is a more precise characterization of this relationship, which here is based on a more basic notion of reduction between distinct models (one from each theory) of a single physical system. Reduction between two such models, I claim, rests on a particular type of approximation relationship between group actions over the models’ state spaces, characterized by a particular function between the model state spaces and a particular subset of the more encompassing model’s state space. Within this approach, I show formally in what sense and under what conditions reduction is transitive, so that reduction of a model 1 to another model 2 and reduction of model 2 to a third model 3 entails direct reduction of model 1 to model 3. Building on this analysis, I consider cases in which reduction of a model 1 to a model 3 may be effected via distinct intermediate models 2a and 2b, and motivate a set of formal consistency requirements between distinct “reduction paths” having the same models as their “end points”. These constraints are explicitly shown to hold in the reduction of a model of non-relativistic classical mechanics (model 1) to a model of relativistic quantum mechanics (model 3), which may be effected by a composite reduction that proceeds either via a model of non-relativistic quantum mechanics (model 2a) or a model of relativistic classical mechanics (model 2b). I offer some brief speculations as to whether and how this sort of consistency requirement might serve to constrain the reductions relating other theories and models, including the relationship that the Standard Model and general relativity must bear to any viable unification of these frameworks.

2019年10月9日 星期三 下午6:00 | | | Wei-Wei Pan, Xiao-Ye Xu, Yaron Kedem, Qin-Qin Wang, Zhe Chen, Munsif Jan, Kai Sun, Jin-Shi Xu, Yong-Jian Han, Chuan-Feng Li, and Guang-Can Guo | | | PRL: General Physics: Statistical and Quantum Mechanics, Quantum Information, etc. |

Author(s): Wei-Wei Pan, Xiao-Ye Xu, Yaron Kedem, Qin-Qin Wang, Zhe Chen, Munsif Jan, Kai Sun, Jin-Shi Xu, Yong-Jian Han, Chuan-Feng Li, and Guang-Can Guo

Researchers have directly measured the components of a nonlocal, entangled wave function, rather than relying on indirect tomographic or reconstructive techniques.

[Phys. Rev. Lett. 123, 150402] Published Wed Oct 09, 2019

2019年10月9日 星期三 下午4:10 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

2019年10月9日 星期三 上午3:28 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

2019年10月9日 星期三 上午3:26 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

2019年10月8日 星期二 下午3:48 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

2019年10月7日 星期一 上午8:00 | | | Stefan Rotter | | | Nature Physics – Issue – nature.com science feeds |

Nature Physics, Published online: 07 October 2019; doi:10.1038/s41567-019-0657-7

Non-Hermitian systems with gain and loss give rise to exceptional points with exceptional properties. An experiment with superconducting qubits now offers a first step towards studying these singularities in the quantum domain.

2019年10月7日 星期一 上午1:57 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

2019年10月7日 星期一 上午1:56 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

2019年10月6日 星期日 下午12:35 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

2019年10月6日 星期日 下午12:27 | | | Philsci-Archive: No conditions. Results ordered -Date Deposited. |

2019年10月2日 星期三 下午12:02 | | | International Journal of Quantum Foundations | | | International Journal of Quantum Foundations |

*Volume 5, Issue 4, pages 115-133*

James L. Beck [Show Biography]

John Bell and others used a locality condition to establish inequalities that they believe must be satisfied by any local hidden-variable model for the spin probability distribution for two entangled particles in an EPR-Bohm experiment. We show that this condition is invalid because it contradicts the product rule of probability theory for any model that exhibits the quantum theory property of perfect correlation. This breaks the connection between Bell inequalities and the existence of any local hidden-variable model of interest. As already known, these inequalities give necessary conditions for the existence of third/fourth-order joint probability distributions for the spin outcomes from three/four separate EPR-Bohm experimental set-ups that are consistent with the second-order joint spin distributions for each experiment after marginalization. If a Bell inequality is violated, as quantum mechanics theory predicts and experiments show can happen, then at least one third-order joint probability is negative. However, this does not imply anything about the existence of local hidden-variable models for the second-order joint probability distributions for the spin outcomes of a single experiment. The locality condition does seem reasonable under the widely-applied frequentist interpretation of the spin probability distributions that views them as real properties of a random process that are manifested through their relative frequency of occurrence, which gives conditioning in the probabilities for the spin outcomes a causal role. In contrast, under the Bayesian interpretation of probability, probabilistic conditioning on one particle’s spin outcome in the product rule is viewed as information to make probabilistic predictions of the other particle’s spin outcome. There is nothing causal and so no reason to develop a locality condition. Thus, how probability is to be interpreted is critical to understanding quantum entanglement and locality.

2019年10月1日 星期二 上午11:03 | | | International Journal of Quantum Foundations | | | International Journal of Quantum Foundations |

*Volume 5, Issue 4, pages 134-146*

Christos Dedes [Show Biography]

A non-linear backward equation with diffusive terms is postulated for the probability density that depends on the Bohmian quantum potential. An associated nonlinear Schroedinger equation is also introduced and extension of the analysis to several particle compounds is sketched along with the implications following from this formalism regarding the non-conservation of probability in the non-equilibrium regime. Some further conclusions are educed with respect to the generalized optical theorem.

2019年10月1日 星期二 上午11:01 | | | International Journal of Quantum Foundations | | | International Journal of Quantum Foundations |

*Volume 5, Issue 4, pages 147-164*

Salim Yasmineh [Show Biography]

This paper aims to give an alternative interpretation of quantum mechanics based on conjecturing the existence of a hidden infinitesimal complex time. It is shown that many features of quantum mechanics emerge from the conjectured hidden-time. The goal of this paper is to better understand quantum phenomena or at least to render them more logical to our understanding.

2019年10月1日 星期二 上午10:59 | | | International Journal of Quantum Foundations | | | International Journal of Quantum Foundations |

*Volume 5, Issue 4, pages 165-185*

Daniel Shanahan [Show Biography]

Various attempts at a thoroughly wave-theoretic explanation of matter have taken as their fundamental ingredient the de Broglie or matter wave. But that wave is superluminal whereas it is implicit in the Lorentz transformation that influences propagate ultimately at the velocity c of light. It is shown that if the de Broglie wave is understood, not as a wave in its own right, but as the relativistically induced modulation of an underlying standing wave comprising counter-propagating influences of velocity c, the energy, momentum, mass and inertia of a massive particle can be explained from the manner in which the modulated wave structure must adapt to a change of inertial frame. With those properties of the particle explained entirely from wave structure, nothing then remains to be apportioned to anything discrete or “solid” within the wave. Consideration may thus be given to the possibility of wave-theoretic explanations of particle trajectories, and to a deeper understanding of the Klein-Gordon, Schroedinger and Dirac equations, all of which were conceived as equations for the de Broglie wave. It is argued that this wave-theoretic interpretation of matter favours a physically realistic, rather than inherently probabilistic, interpretation of quantum mechanics.

2019年10月1日 星期二 上午10:57 | | | International Journal of Quantum Foundations | | | International Journal of Quantum Foundations |

*Volume 5, Issue 4, pages 186-188*

Peter J. Lewis [Show Biography]

This is a review of Michael Silberstein, W. M. Stuckey, and Timothy McDevitt’s book Beyond the Dynamical Universe: Unifying Block Universe Physics and Time as Experienced (Oxford University Press, 2018).

Full Text Download (305k)

# Quantum statistics in Bohmian trajectory gravity

T C Andersen

Published under licence by IOP Publishing Ltd

, ,

## Abstract

The recent experimental proposals by Bose et al. and Marletto et al. (BMV) outline a way to test for the quantum nature of gravity by measuring gravitationally induced differential phase accumulation over the superposed paths of two ~ 10^{−14} *kg* masses. These authors outline the expected outcome of these experiments for semi-classical, quantum gravity and collapse models. It is found that both semi-classical and collapse models predict a lack of entanglement in the experimental results. This work predicts the outcome of the BMV experiment in Bohmian trajectory gravity – where classical gravity is assumed to couple to the particle configuration in each Bohmian path, as opposed to semi-classical gravity where gravity couples to the expectation value of the wave function, or of quantized gravity, where the gravitational field is itself in a quantum superposition. In the case of the BMV experiment, Bohmian trajectory gravity predicts that there will be quantum entanglement. This is surprising as the gravitational field is treated classically. A discussion of how Bohmian trajectory gravity can induce quantum entanglement for a non superposed gravitational field is put forward.

# Event-Based Quantum Mechanics: A Context for the Emergence of Classical Information

## Abstract

It is shown that, for a de Sitter Universe, the Hartle-Hawking (HH) wave function can be obtained in a simple way starting from the Friedmann-Lemaitre-Robertson-Walker (FLRW) line element of cosmological equations. An oscillator having imaginary time is indeed derived starting from the Hamiltonian obtaining the HH condition. This proposes again some crucial matter on the meaning of complex time in cosmology. In order to overcome such difficulties, we propose an interpretation of the HH framework based on de Sitter Projective Holography.