Weekly Papers on Quantum Foundations (27)

Traveling time in a spacetime-symmetric extension of nonrelativistic quantum mechanics 

from 

PRA – fundamentalconcepts

 by 

Arlans J. S. de Lara and Marcus W. Beims

Fri Jul 12 2024 18:00:00 (15 hours)

# 1.

Author(s): Arlans J. S. de Lara and Marcus W. Beims

Time continues to be an intriguing physical property in the modern era. On the one hand, we have the classical and relativistic notion of time, where space and time have the same hierarchy, essential in describing events in spacetime. On the other hand, in quantum mechanics, time appears as a classi…

[Phys. Rev. A 110, 012216] Published Fri Jul 12, 2024

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Single-Photon Interference over 8.4 km Urban Atmosphere: Toward Testing Quantum Effects in Curved Spacetime with Photons 

from 

PRL

 by 

Hui-Nan Wu, Yu-Huai Li, Bo Li, Xiang You, Run-Ze Liu, Ji-Gang Ren, Juan Yin, Chao-Yang Lu, Yuan Cao, Cheng-Zhi Peng, and Jian-Wei Pan

Fri Jul 12 2024 18:00:00 (15 hours)

# 2.

Author(s): Hui-Nan Wu, Yu-Huai Li, Bo Li, Xiang You, Run-Ze Liu, Ji-Gang Ren, Juan Yin, Chao-Yang Lu, Yuan Cao, Cheng-Zhi Peng, and Jian-Wei Pan

The emergence of quantum mechanics and general relativity has transformed our understanding of the natural world significantly. However, integrating these two theories presents immense challenges, and their interplay remains untested. Recent theoretical studies suggest that the single-photon interfe…

[Phys. Rev. Lett. 133, 020201] Published Fri Jul 12, 2024

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The Time in Thermal Time 

from 

philsci

Fri Jul 12 2024 16:10:00 (16 hours)

# 3.

Chua, Eugene Y. S. (2024) The Time in Thermal Time. [Preprint]

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Princeton seminars on physics and philosophy 

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philsci

Fri Jul 12 2024 16:09:08 (16 hours)

# 4.

Rovelli, Carlo (2024) Princeton seminars on physics and philosophy. [Preprint]

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Precision is not limited by the second law of thermodynamics 

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quant-ph

 by 

Florian Meier, Yuri Minoguchi, Simon Sundelin, Tony J. G. Apollaro, Paul Erker, Simone Gasparinetti, Marcus Huber

Fri Jul 12 2024 12:24:26 (20 hours)

# 5.

arXiv:2407.07948v1 Announce Type: new Abstract: Physical devices operating out of equilibrium are inherently affected by thermal fluctuations, limiting their operational precision. This issue is pronounced at microscopic and especially quantum scales and can only be mitigated by incurring additional entropy dissipation. Understanding this constraint is crucial for both fundamental physics and technological design. For instance, clocks are inherently governed by the second law of thermodynamics and need a thermodynamic flux towards equilibrium to measure time, which results in a minimum entropy dissipation per clock tick. Classical and quantum models and experiments often show a linear relationship between precision and dissipation, but the ultimate bounds on this relationship are unknown. Our theoretical discovery presents an extensible quantum many-body system that achieves clock precision scaling exponentially with entropy dissipation. This finding demonstrates that coherent quantum dynamics can surpass the traditional thermodynamic precision limits, potentially guiding the development of future high-precision, low-dissipation quantum devices.

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Derivations of Bloch (Majorana–Bloch) equation, von Neumann equation, and Schr\”odinger–Pauli equation 

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quant-ph

 by 

Lihong V. Wang

Fri Jul 12 2024 12:24:17 (20 hours)

# 6.

arXiv:2407.08025v1 Announce Type: new Abstract: The transition from classical physics to quantum mechanics has been mysterious. Here, we derive the space-independent von Neumann equation for electron spin mathematically from the classical Bloch or Majorana–Bloch equation, which is also derived. Subsequently, the space-independent Schr\”odinger–Pauli equation is derived in both the quantum mechanical and recently developed co-quantum dynamic frameworks.

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From global time to local physics 

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gr-qc

 by 

Syed Moeez Hassan, Viqar Husain, Babar Qureshi

Fri Jul 12 2024 12:24:16 (20 hours)

# 7.

arXiv:2407.08283v1 Announce Type: new Abstract: Global time is a gauge or relational choice of time variable in canonical gravity. Local time is the time used in a flat patch of spacetime. We compare the dynamics of a scalar field with respect to choices of global time and Minkowski patch time in an expanding cosmology. Our main results are that evolutions starting from the same initial conditions are similar on the time scales of terrestrial experiments, and that global time leads to a mechanism for evolving coupling constants.

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Symmetries and singular behaviors with Bohmian trajectories 

from 

quant-ph

 by 

A. S. Sanz

Fri Jul 12 2024 12:24:15 (20 hours)

# 8.

arXiv:2407.08096v1 Announce Type: new Abstract: Quantum mechanics is able to produce challenging behaviors even in the simplest situations. This is possible because of the important dynamical role that phase plays in the evolution of quantum systems, very similar, nonetheless, to effects observable in analogous optical systems. The present work focuses on how Bohmian mechanics proves to be a rather convenient theoretical framework to analyze phase-based phenomena, since the phase constitutes the central element in this hydrodynamical formulation of quantum mechanics. More specifically, it allows us to understand how spatial phase variations give rise to velocity fields that eventually rule the dynamical behavior of quantum systems, and that, when integrated in time locally (i.e., taking into account specific positions), they provide us with a neat local (point by point) description of the system evolution in the configuration space. Indeed, it will also be seen that this idea transcends the quantum realm and can be profitably used to describe the behavior of optical analogs with rather singular behaviors. With this purpose, two interesting phenomena that take place in free space are considered, namely, the self-acceleration and shape-invariance of Airy beams, and spontaneous self-focusing.

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Nonlocal Locking of Observable Quantities: A Faithful Signature of Nonclassical Correlations 

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quant-ph

 by 

Mir Alimuddin, Snehasish Roy Chowdhury, Ram Krishna Patra, Subhendu B. Ghosh, Tommaso Tufarelli, Gerardo Adesso, Manik Banik

Fri Jul 12 2024 12:24:11 (20 hours)

# 9.

arXiv:2407.08292v1 Announce Type: new Abstract: Nonclassicality in composite quantum systems depicts several puzzling manifestations, with Einstein-Podolsky-Rosen entanglement, Schr\”odinger steering, and Bell nonlocality being the most celebrated ones. In addition to those, an unentangled quantum state can also exhibit nonclassicality, as evidenced from notions such as quantum discord and work deficit. Here, we propose a general framework to investigate nonclassical correlations in multipartite quantum states. The distinct signatures left on observable quantities, depending on whether the sub-parts of a composite system are probed separately or jointly, provide an operational avenue to construct different quantifiers that faithfully capture signatures of nonclassicality in quantum states. Along the line we unveil an intriguing phenomenon referred to as `nonlocal locking of observable quantities’, where the value of an observable quantity gets locked in the correlation of a nonclassical state. Our approach reduces the experimental demand for verification of nonclassicality in composite systems and can find applications for enhanced energy storage in quantum thermodynamical devices.

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Quantum Mechanics as a Carnapian Language 

from 

physics.hist-ph

 by 

Iulian D. Toader

Thu Jul 11 2024 12:13:53 (1 day)

# 10.

arXiv:2407.07102v1 Announce Type: new Abstract: The paper discusses Carnap’s claim that a proper philosophical analysis of quantum mechanics, including a determination of whether its logic has to be revised, requires a rational reconstruction of the theory. Several articulations of the notion of rational reconstruction are recalled, followed by a brief analysis of two standard criticisms of Carnap’s claim. The paper suggests that adopting inferentialism overcomes both criticisms, and then considers the possibility of formulating quantum mechanics as a Carnapian language with an inferentialist semantics.

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Metaphysics and Convention in Dimensional Analysis, 1914-1917 

from 

philsci

Thu Jul 11 2024 05:57:04 (2 days)

# 11.

Jalloh, Mahmoud (2024) Metaphysics and Convention in Dimensional Analysis, 1914-1917. [Preprint]

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The Bridgman-Tolman-Warburton Correspondence on Dimensional Analysis, 1934 

from 

philsci

Thu Jul 11 2024 05:56:16 (2 days)

# 12.

Jalloh, Mahmoud (2024) The Bridgman-Tolman-Warburton Correspondence on Dimensional Analysis, 1934. [Preprint]

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Is time one-dimensional? 

from 

physics.hist-ph

 by 

Francisco Caruso

Wed Jul 10 2024 12:24:27 (2 days)

# 13.

arXiv:2407.06218v1 Announce Type: new Abstract: In the History of Ideas, a succession of philosophical and scientific achievements, concerning the concept of space and its dimensionality, were essential to contribute, after a long period, to the theoretical possibility of thinking physical time with more than one dimension. Meanwhile, such a progress brought with it the expectation that one can either understand the role of dimensionality in the World or disclose how certain physical phenomena depend on it. Some of these issues are sketched throughout the text, as well as those remarkable moments in the History of Science where important contributions were made in order to give a satisfactory answer to the following inescapable question: — How many dimensions does time have?

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Dressing vs. Fixing: On How to Extract and Interpret Gauge-Invariant Content 

from 

physics.hist-ph

 by 

Philipp Berghofer, Jordan Fran\c{c}ois

Tue Jul 09 2024 12:03:42 (3 days)

# 14.

arXiv:2404.18582v3 Announce Type: replace Abstract: There is solid consensus among physicists and philosophers that, in gauge field theory, for a quantity to be physically meaningful or real, it must be gauge-invariant. Yet, every “elementary” field in the Standard Model of particle physics is actually gauge-variant. This has led a number of researchers to insist that new manifestly gauge-invariant approaches must be established. Indeed, in the foundational literature, dissatisfaction with standard methods for reducing gauge symmetries has been expressed: Spontaneous symmetry breaking is deemed conceptually dubious, while gauge fixing suffers the same limitations and is subject to the same criticisms as coordinate choices in General Relativity. An alternative gauge-invariant proposal was recently introduced in the literature, the so-called “dressing field method” (DFM). It is a mathematically subtle tool, and unfortunately prone to be confused with simple gauge transformations, hence with standard gauge~fixings. As a matter of fact, in the physics literature the two are often conflated, and in the philosophy community some doubts have been raised about whether there is any substantial difference between them. Clarifying this issue is of special significance for anyone interested in both the foundational issues of gauge theories and their invariant formulation. It is thus our objective to establish as precisely as possible the technical and conceptual distinctions between the DFM and gauge fixing.

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Efficient optimization of deep neural quantum states 

from 

nature-physics

Tue Jul 09 2024 08:00:00 (4 days)

# 15.

Nature Physics, Published online: 09 July 2024; doi:10.1038/s41567-024-02567-0An improved optimization algorithm enables the training of large-scale neural quantum states in which the enormous number of neuron connections capture the intricate complexity of quantum many-body wavefunctions. This advance leads to unprecedented accuracy in paradigmatic quantum models, opening up new avenues for simulating and understanding complex quantum phenomena.

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On the growing universe of causal set theory – an order-type approach 

from 

philsci

Tue Jul 09 2024 02:59:14 (4 days)

# 16.

Placek, Tomasz and Wronski, Leszek (2024) On the growing universe of causal set theory – an order-type approach. Found Phys, 54 (42).

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Constants in disguise 

from 

nature-physics

 by 

Karen Mudryk

Mon Jul 08 2024 08:00:00 (5 days)

# 17.

Nature Physics, Published online: 08 July 2024; doi:10.1038/s41567-024-02583-0It has many names and yet no name. The designation of the universal gas constant as R has remained a mystery, as Karen Mudryk recounts.

arxiv > quant-ph > arXiv:2406.19419

Price-Wharton Constrained Colliders: Co-Causation or No Causation?

W.M. StuckeyMichael Silberstein

Price and Wharton have recently suggested that “constrained retrocausal collider bias is the origin of entanglement.” In this paper, we argue that their connection across a constrained collider (CCC) for the V-shaped case with the Bell states is not “a mechanism for entanglement,” providing a negative answer to the title of arXiv:2406.04571. Rather, CCC should be viewed as a novel approach to the causal modeling of entanglement, providing a perspectival co-causal relationship between the two wings of the experiment that does not violate locality or statistical independence. The key is to accept that quantum mechanics is complete, so the Bell states provide the “mechanism for entanglement” and CCC provides a causal model of entanglement per causal perspectivalism in accord with the different subjective spacetime models of the experiment. When combined into an objective spacetime model of the experiment, the subjective co-causation disappears leaving an objective acausal view of entanglement in accord with the quantum reconstruction program. Essentially, the quantum reconstruction program has rendered quantum mechanics a principle theory based on the observer-independence of Planck’s constant h as justified by the relativity principle (“no preferred reference frame” NPRF), exactly as special relativity is a principle theory based on the observer-independence of the speed of light c as justified by the relativity principle. Thus, NPRF + c is an adynamical global constraint on the configuration of worldtubes for the equipment in the experiment while NPRF + h is an adynamical global constraint on the distribution of quantum detection events in that context. Accordingly, CCC then provides a new way to understand causation subjectively per causal perspectivalism in this objectively acausal spacetime model of the experiment.

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