Weekly Papers on Quantum Foundations (15)

This is a list of this week’s papers on quantum foundations published in the various journals or uploaded to the preprint servers such as arxiv.org and PhilSci Archive.

[Perspective] Assembling a complex quantum ensemble

Science: Current Issue

on 2015-4-10 12:00am GMT

Statistical mechanics provides a systematic approach for predicting the behavior of systems when only partial information is present. The key assumption underlying all of statistical mechanics is that every allowed configuration of the system, called a microstate, occurs with equal probability. This approach, valid for both classical and quantum systems, requires only minimal additional information for it to be astonishingly predictive. On page 207 of this issue, Langen et al. (1) describe a system in which this paradigm is violated and conventional statistical mechanics fails; almost all of the usually allowed microstates are inaccessible via the system’s dynamics. Author: I. B. Spielman

Five Departures in Logic, Mathematics, and thus—Whether We Like It, or Not—in Physics as Well…

Latest Results for Foundations of Physics

on 2015-4-08 12:00am GMT

Abstract

Physics depends on “physical intuition”, much of which is formulated in terms of Mathematics. Mathematics itself depends on Logic. The paper presents three latest novelties in Logic which have major consequences in Mathematics. Further, it presents two possible significant departures in Mathematics itself. These five departures can have major implications in Physics. Some of them are indicated, among them in Quantum Mechanics and Relativity.

Unifying Framework for Relaxations of the Causal Assumptions in Bell’s Theorem

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

on 2015-4-07 2:00pm GMT

Author(s): R. Chaves, R. Kueng, J. B. Brask, and D. Gross

Bell’s theorem shows that quantum mechanical correlations can violate the constraints that the causal structure of certain experiments impose on any classical explanation. It is thus natural to ask to which degree the causal assumptions—e.g., locality or measurement independence—have to be relaxed i…

[Phys. Rev. Lett. 114, 140403] Published Tue Apr 07, 2015

The Problem of Confirmation in the Everett Interpretation. (arXiv:1504.01063v1 [physics.hist-ph])

physics.hist-ph updates on arXiv.org

on 2015-4-07 1:23am GMT

Authors: Emily Adlam

I argue that the Oxford school Everett interpretation is internally incoherent, because we cannot claim that in an Everettian universe the kinds of reasoning we have used to arrive at our beliefs about quantum mechanics would lead us to form true beliefs. I show that in an Everettian context, the experimental evidence that we have available could not provide empirical confirmation for quantum mechanics, and moreover that we would not even be able to establish reference to the theoretical entities of quantum mechanics. I then consider a range of existing Everettian approaches to the probability problem and show that they do not succeed in overcoming this incoherence.moon bounce for sale

Spin as a Determinable

Latest Results for Topoi

on 2015-4-07 12:00am GMT

Abstract

In this paper I aim to answer two questions: (1) Can spin be treated as a determinable? (2) Can a treatment of spin as a determinable be used to understand quantum indeterminacy? In response to the first question I show that the relations among spin number, spin components and spin values cannot be captured by a single determination relation; instead we need to look at spin number and spin value separately. In response to the second question I discuss three ways in which the determinables model might be modified to account for indeterminacy, and argue that none of them is fully successful in helping us to understand quantum indeterminacy.

The Universal and the Local in Quantum Theory

Latest Results for Topoi

on 2015-4-07 12:00am GMT

Abstract

Any empirical physical theory must have implications for observable events at the scale of everyday life, even though that scale plays no special role in the basic ontology of the theory itself. The fundamental physical scales are microscopic for the “local beables” of the theory and universal scale for the non-local beables (if any). This situation creates strong demands for any precise quantum theory. This paper examines those constraints, and illustrates some ways in which they can be met.

A Categorial Semantic Representation of Quantum Event Structures

PhilSci-Archive: No conditions. Results ordered -Date Deposited.

on 2015-4-06 10:57pm GMT

Zafiris, Elias and Karakostas, Vassilios (2013) A Categorial Semantic Representation of Quantum Event Structures. [Published Article]

Measurement and Fundamental Processes in Quantum Mechanics

Latest Results for Foundations of Physics

on 2015-4-04 12:00am GMT

Abstract

In the standard mathematical formulation of quantum mechanics, measurement is an additional, exceptional fundamental process rather than an often complex, but ordinary process which happens also to serve a particular epistemic function: during a measurement of one of its properties which is not already determined by a preceding measurement, a measured system, even if closed, is taken to change its state discontinuously rather than continuously as is usual. Many, including Bell, have been concerned about the fundamental role thus given to measurement in the foundation of the theory. Others, including the early Bohr and Schwinger, have suggested that quantum mechanics naturally incorporates the unavoidable uncontrollable disturbance of physical state that accompanies any local measurement without the need for an exceptional fundamental process or a special measurement theory. Disturbance is unanalyzable for Bohr, but for Schwinger it is due to physical interactions’ being borne by fundamental particles having discrete properties and behavior which is beyond physical control. Here, Schwinger’s approach is distinguished from more well known treatments of measurement, with the conclusion that, unlike most, it does not suffer under Bell’s critique of quantum measurement. Finally, Schwinger’s critique of measurement theory is explicated as a call for a deeper investigation of measurement processes that requires the use of a theory of quantum fields.

 

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