Weekly Papers on Quantum Foundations (39)

Objective consequentialism and the plurality of chances

上午8:00

Latest Results for Synthese

Abstract

Williams and J. Fraser have recently argued that effective field theory methods enable scientific realists to make more reliable ontological commitments in quantum field theory (QFT) than those commonly made. In this paper, I show that the interpretative relevance of these methods extends beyond the specific context of QFT by identifying common structural features shared by effective theories across physics. In particular, I argue that effective theories are best characterized by the fact that they contain intrinsic empirical limitations, and I extract from their structure one central interpretative constraint for making more reliable ontological commitments in different subfields of physics. While this is in principle good news, this constraint still raises a challenge for scientific realists in some contexts, and I bring the point home by focusing on Williams’s and J. Fraser’s defense of selective realism in QFT.

Work done in a decoherence process. (arXiv:2109.09135v2 [quant-ph] UPDATED)

上午10:05

Gianluca Francica

quant-ph updates on arXiv.org

We investigate the thermodynamics of a quench realized by turning on an interaction generating pure decoherence. We characterize the work probability distribution function, also with a fluctuation relation, a lower bound of the work and by considering some physical examples.

From the Heisenberg to the Schr\”{o}dinger Picture: Quantum Stochastic Processes and Process Tensors. (arXiv:2109.09256v2 [quant-ph] UPDATED)

上午10:05

Hendra I. Nurdin, John E. Gough

quant-ph updates on arXiv.org

A general theory of quantum stochastic processes was formulated by Accardi, Frigerio and Lewis in 1982 within the operator-algebraic framework of quantum probability theory, as a non-commutative extension of the Kolmogorovian classical stochastic processes. More recently, studies on non-Markovian quantum processes have led to the discrete-time process tensor formalism in the Schr\”{o}dinger picture to describe the outcomes of sequential interventions on open quantum systems. However, there has been no treatment of the relationship of the process tensor formalism to the quantum probabilistic theory of quantum stochastic processes. This paper gives an exposition of quantum stochastic processes and the process tensor and the relationship between them. In particular, it is shown how the latter emerges from the former via extended correlation kernels incorporating ancillas.

Reply to superdeterminists on the hidden-variable formulation of Invariant-set theory. (arXiv:2109.11109v1 [quant-ph])

上午10:05

physics.hist-ph updates on arXiv.org

Authors: Indrajit Sen

In a recent article (arXiv:2108.08144), Hance, Hossenfelder and Palmer have advanced arguments claiming to show that the analysis of Invariant-set theory in a hidden-variable setting (arXiv:2107.04761) is wrong. We explain here why these arguments are incorrect, and involve misunderstandings of the hidden-variable model in question and Bell’s notion of local causality.

Life, the universe and the hidden meaning of everything. (arXiv:2109.10241v2 [physics.hist-ph] UPDATED)

上午10:05

physics.hist-ph updates on arXiv.org

Authors: Zhi-Wei Wang, Samuel L. Braunstein

It is hard to look at the universe and not wonder about the meaning, of, well, everything. A natural question is whether what we see is a sign of intelligent design. The antithesis of design would be a random universe or, assuming laws of physics, one whose fundamental physical parameters were randomly selected, but conditioned on life (ourselves) being here to observe it. In unpublished work, the British physicist Dennis Sciama argued that such a randomly selected universe would display a statistical signature. He concluded that a random universe would almost certainly have parameters only just allowing for the possibility of life. Here we consider whether this signature is definitive. We find that with plausible additional assumptions Sciama’s signature would appear to reverse: Were our universe random, it could give the false impression of being intelligently designed, with the fundamental constants appearing to be fine-tuned to a strong probability for life to emerge and be maintained.

On the energy of gravitational waves. (arXiv:2109.06864v2 [gr-qc] UPDATED)

上午10:05

gr-qc updates on arXiv.org

Authors: Rong-Gen Cai, Xing-Yu Yang, Long Zhao

The energy of gravitational waves (GWs) is a fundamental problem in gravity theory. The existing descriptions for the energy of GWs, such as the well-known Isaacson energy-momentum tensor, suffer from several defects. Due to the equivalence principle, the gravitational energy-momentum can only be defined quasilocally, being associated with a closed spacelike 2-surface bounding a region. We propose a new approach to derive the energy of GWs directly from the quasilocal gravitational energy. Such an approach is natural and consistent with the quasilocality of gravitational energy-momentum, and it is valid for GWs with any wavelengths in any order of perturbations.

Quantum Hypothesis Testing for Exoplanet Detection

2021年9月23日星期四下午6:00

Zixin Huang and Cosmo Lupo

PRL: General Physics: Statistical and Quantum Mechanics, Quantum Information, etc.

Author(s): Zixin Huang and Cosmo Lupo

Treating stars and planets as quantum objects could make it easier for astronomers to directly image exoplanets.

[Phys. Rev. Lett. 127, 130502] Published Thu Sep 23, 2021

ΛCDM and MOND: A Debate about Models or Theory?

2021年9月22日星期三下午4:19