Weekly Papers on Quantum Foundations (34)

Magic of the Heisenberg Picture 

from 

quant-ph

 by 

Neil Dowling, Pavel Kos, Xhek Turkeshi

Fri Aug 30 2024 12:00:00 (21 hours)

# 1.

arXiv:2408.16047v1 Announce Type: new Abstract: Magic quantifies the non-Clifford operations required for preparing a state on quantum processors and sets bounds on the classical computational complexity of simulating quantum dynamics. We study a magic resource theory for operators, which is dual to that describing states. We identify that the stabilizer R\’enyi entropy analog in operator space is a good magic monotone satisfying the usual conditions, while inheriting efficient computability properties and providing a tight lower-bound to the minimum number of non-Clifford gates in a circuit. It is operationally well-defined as quantifying how well one can approximate an operator with one that has only few Pauli strings; analogous to the relation between entanglement entropy and tensor-network truncation. An immediate advantage is that the operator stabilizer entropies exhibit inherent locality through a Lieb-Robinson bound, making them particularly suited for studying local dynamic magic generation in many-body systems. We compute this quantity analytically in two distinct regimes. First, we show that random evolution or circuits typically have approximately maximal magic in the Heisenberg picture for all R\’enyi indices, and evaluate the Page correction. Second, harnessing both dual unitarity and ZX graphical calculus, we compute the operator stabilizer entropy evolution for an interacting integrable XXZ circuit. In this case, magic quickly saturates to a constant; a distinct Heisenberg picture phenomena and suggestive of a connection to integrability. We argue that this efficiently computable operator magic monotone reveals structural properties of many-body magic generation, and can inspire novel Clifford-assisted tensor network methods.

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Weyl’s Quantifiers 

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philsci

Fri Aug 30 2024 01:56:40 (1 day)

# 2.

Toader, Iulian Danut (2024) Weyl’s Quantifiers. [Preprint]

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Bell’s Theorem Begs the Question 

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philsci

Thu Aug 29 2024 17:04:20 (1 day)

# 3.

Christian, Joy (2024) Bell’s Theorem Begs the Question. [Preprint]

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Comment on the GHZ variant of Bell’s theorem without inequalities 

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philsci

Thu Aug 29 2024 16:09:54 (1 day)

# 4.

Christian, Joy (2024) Comment on the GHZ variant of Bell’s theorem without inequalities. [Preprint]

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The two-spin enigma: from the helium atom to quantum ontology 

from 

physics.hist-ph

 by 

Philippe Grangier, Alexia Auffeves, Nayla Farouki, Mathias Van Den Bossche, Olivier Ezratty

Thu Aug 29 2024 12:00:00 (1 day)

# 5.

arXiv:2406.05169v2 Announce Type: replace Abstract: The purpose of this article is to provide a novel approach and justification of the idea that classical physics and quantum physics can neither function nor even be conceived one without the other – in line with ideas attributed to e.g. Niels Bohr or Lev Landau. Though this point of view may go against current common wisdom, we will show that it perfectly fits with empirical evidence, and can be maintained without giving up physical realism. In order to place our arguments in a convenient historical perspective, we will proceed as if we were following the path of a police investigation, about the demise, or vanishing, of some valuable properties of the two electrons in the helium atom. We will start from experimentally based evidence in order to analyse and explain physical facts, moving cautiously from a classical to a quantum description, without mixing them up. The overall picture will be that the physical properties of microscopic systems are quantized, as initially shown by Planck and Einstein, and they are also contextual, i.e. that they can be given a physical sense only by embedding a microscopic system within a macroscopic measurement context.

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(Split-)Quaternion and (Split-)Octonion Dynamics in Discrete-Time Recurrent Frenet Frames 

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philsci

Thu Aug 29 2024 01:42:04 (2 days)

# 6.

Binder, Bernd (2024) (Split-)Quaternion and (Split-)Octonion Dynamics in Discrete-Time Recurrent Frenet Frames. [Preprint]

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The Extended Hamiltonian Is Not Trivial 

from 

philsci

Wed Aug 28 2024 15:35:51 (2 days)

# 7.

Bradley, Clara (2024) The Extended Hamiltonian Is Not Trivial. [Preprint]

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The Relationship Between Lagrangian and Hamiltonian Mechanics: The Irregular Case 

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philsci

Wed Aug 28 2024 15:35:41 (2 days)

# 8.

Bradley, Clara (2024) The Relationship Between Lagrangian and Hamiltonian Mechanics: The Irregular Case. [Preprint]

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Do First-Class Constraints Generate Gauge Transformations? A Geometric Resolution 

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philsci

Wed Aug 28 2024 15:35:30 (2 days)

# 9.

Bradley, Clara (2024) Do First-Class Constraints Generate Gauge Transformations? A Geometric Resolution. [Preprint]

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Feynman 1947 letter on path integral for the Dirac equation 

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physics.hist-ph

 by 

Ted Jacobson

Wed Aug 28 2024 12:00:00 (2 days)

# 10.

arXiv:2408.15070v1 Announce Type: new Abstract: In 1947, four months before the famous Shelter Island conference, Richard Feynman wrote a lengthy letter to his former MIT classmate Theodore Welton, reporting on his efforts to develop a path integral describing the propagation of a Dirac particle. While these efforts never came to fruition, and were shortly abandoned in favor of a very different method of dealing with the electron propagator appearing in in QED, the letter is interesting both from the historical viewpoint of revealing what Feynman was thinking about during that period just before the development of QED, and for its scientific ideas. It also contains at the end some philosophical remarks, which Feynman wraps up with the comment, “Well enough for the baloney.” In this article I present a transcription of the letter along with editorial notes, and a facsimile of the original handwritten document. I also briefly comment on Feynman’s efforts and discuss their relation to some later work.

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Evidence of Dark Energy Prior to its Discovery 

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physics.hist-ph

 by 

Geoffrey W. Marcy

Tue Aug 27 2024 12:00:00 (3 days)

# 11.

arXiv:2408.13427v1 Announce Type: cross Abstract: This is a review and statistical analysis of the evidence supporting the existence of a cosmological constant in the early 1990s, before its discovery made with distant supernovae in 1998. The earlier evidence was derived from newly precise measurements of the Universe, including its mass density, the Hubble constant, the age of the oldest stars, the filamentary large-scale structure, and the anisotropy of the cosmic microwave background. These measurements created tension for models assuming the cosmological constant was zero. This tension was alleviated by several insightful papers published before 1996, which proposed a cosmological constant that increased the expansion rate. Statistical analysis here shows that the probability of the cosmological constant being zero was demonstrably less than a few percent. Some models identified a best-fit value close to the modern estimate of Omega_Lambda ~ 0.7.

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The Philosophy of Science of Consciousness Science 

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philsci

Tue Aug 27 2024 03:10:42 (4 days)

# 12.

Negro, Niccolo and Hohwy, Jakob and Corcoran, Andrew and Mudrik, Liad (2024) The Philosophy of Science of Consciousness Science. [Preprint]

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Equivalence, reduction, and sophistication in teleparallel gravity 

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philsci

Tue Aug 27 2024 02:53:13 (4 days)

# 13.

Chen, Lu and March, Eleanor and Read, James (2024) Equivalence, reduction, and sophistication in teleparallel gravity. [Preprint]

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Wigner function properties for electromagnetic systems 

from 

PRA – fundamentalconcepts

 by 

E. E. Perepelkin, B. I. Sadovnikov, N. G. Inozemtseva, and P. V. Afonin

Mon Aug 26 2024 18:00:00 (4 days)

# 14.

Author(s): E. E. Perepelkin, B. I. Sadovnikov, N. G. Inozemtseva, and P. V. Afonin

Using the Wigner-Vlasov formalism, an exact three-dimensional solution of the Schrödinger equation for a scalar particle in an electromagnetic field is constructed. Electric and magnetic fields are nonuniform. According to the exact expression for the wave function, the search for two types of Wigne…

[Phys. Rev. A 110, 022224] Published Mon Aug 26, 2024

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