Weekly Papers on Quantum Foundations (51)

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

Logarithmic corrections to black hole entropy from Kerr/CFT. (arXiv:1612.04833v1 [hep-th])

hep-th updates on arXiv.org

on 2016-12-17 1:55am GMT

Authors: Abhishek PathakAchilleas P. PorfyriadisAndrew StromingerOscar Varela

It has been shown by A. Sen that logarithmic corrections to the black hole area-entropy law are entirely determined macroscopically from the massless particle spectrum. They therefore serve as powerful consistency checks on any proposed enumeration of quantum black hole microstates. Sen’s results include a macroscopic computation of the logarithmic corrections for a five-dimensional near extremal Kerr-Newman black hole. Here we compute these corrections microscopically using a stringy embedding of the Kerr/CFT correspondence and find perfect agreement.

How the Result of Counting One Photon Can Turn Out to Be a Value of 8. (arXiv:1612.04920v1 [quant-ph])

quant-ph updates on arXiv.org

on 2016-12-17 1:55am GMT

Authors: Matin HallajiAmir FeizpourGreg DmochowskiJosiah SinclairAephraim M. Steinberg

In 1988, Aharonov, Albert, and Vaidman introduced a new paradigm of quantum measurement in a paper which had the unwieldy but provocative title “How the result of a measurement of a component of the spin of a spin-1=2 particle can turn out to be 100.” This paradigm, so-called “weak measurement,” has since been the subject of widespread theoretical and experimental attention, both for the perspective it offers on quantum reality and for possible applications to precision measurement. Yet almost all of the weak-measurement experiments carried out so far could be alternatively understood in terms of the classical (electro-magnetic wave) theory of optics. Here we present a truly quantum version, the first in which a measurement apparatus deterministically entangles two distinct optical beams, enabling us to experimentally ask a question directly analogous to that of the original proposal: “In a two-arm interferometer containing one photon in total, can the result of a measurement of the photon number in one arm turn out to be greater than 1?” Specifically, we show that a single photon, when properly post-selected, can have an effect equal to that of eight photons: that is, in a system where a single photon has been calibrated to write a nonlinear phase shift of \phi_0 on a probe beam, we measure phase shifts as large as 8\phi_0 for appropriately post-selected single photons. This is the first deterministic weak-value experiment in optics which defies classical explanation, and constitutes a realization of our proposal for weak-value amplification (WVA) of the small optical nonlinearity at the single-photon level. It opens up a new regime for the study of entanglement of optical beams, as well as further investigations of the power of WVA for the measurement of small quantities.

The origins of the research on the foundations of quantum mechanics (and other critical activities) in Italy during the 1970s

ScienceDirect Publication: Studies in History and Philosophy of Science Part B: Studies in History and Philosophy of Modern Physics

on 2016-12-16 1:14pm GMT

Publication date: Available online 14 December 2016
Source:Studies in History and Philosophy of Science Part B: Studies in History and Philosophy of Modern Physics
Author(s): Angelo Baracca, Silvio Bergia, Flavio Del Santo
We present a reconstruction of the studies on the Foundations of Quantum Mechanics carried out in Italy at the turn of the 1960s. Actually, they preceded the revival of the interest of the American physicists towards the foundations of quantum mechanics around mid-1970s, recently reconstructed by David Kaiser in a book of 2011. An element common to both cases is the role played by the young generation, even though the respective motivations were quite different. In the US they reacted to research cuts after the war in Vietnam, and were inspired by the New Age mood. In Italy the dissatisfaction of the young generations was rooted in the student protests of 1968 and the subsequent labour and social fights, which challenged the role of scientists. The young generations of physicists searched for new scientific approaches and challenged their own scientific knowledge and role. The criticism to the foundations of quantum mechanics and the perspectives of submitting them to experimental tests were perceived as an innovative research field and this attitude was directly linked to the search for an innovative and radical approach in the history of science. All these initiatives gave rise to booming activity throughout the 1970s, contributing to influence the scientific attitude and the teaching approach.

Quantum Relativity

Latest Results for International Journal of Theoretical Physics

on 2016-12-14 12:00am GMT

On time, causation and explanation in the causally symmetric Bohmian model of quantum mechanics

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

on 2016-12-13 9:52pm GMT

Berkovitz, Joseph (2016) On time, causation and explanation in the causally symmetric Bohmian model of quantum mechanics. [Preprint]

The Role of Idealizations in the Aharonov-Bohm Effect

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

on 2016-12-13 9:48pm GMT

Earman, John (2016) The Role of Idealizations in the Aharonov-Bohm Effect. [Preprint]

Further Considerations Regarding the Aharonov-Bohm Effect and the Wavefunction of the Entire System

Latest Results for International Journal of Theoretical Physics

on 2016-12-13 12:00am GMT

Abstract

In an earlier paper it was demonstrated that the hypothesized electrostatic version of the Aharonov-Bohm (“AB”) effect does not exist. The conclusion follows straightforwardly once one recognizes that interference takes place in the configuration space of the entire system, including the experimental apparatus, and the wavefunction of the apparatus cannot be ignored. Two additional results are presented here. 1. Observations of interference that had been attributed to an analogue of the electrostatic AB effect (or “scalar effect”) are actually due to a magnetic AB effect. 2. In the original magnetic AB effect itself, there is no phase shift if it is possible effectively to shield the solenoid from the influence of the passing electron. This result is not in conflict with the landmark experiments of Tonomura and colleagues if Wang’s recent claim is correct, that superconductive shielding could not have isolated the toroidal magnet from the magnetic pulse of the passing electron.

An Everett Perspective on Bohr and EPR

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

on 2016-12-12 8:03pm GMT

Bacciagaluppi, Guido (2016) An Everett Perspective on Bohr and EPR. [Preprint]

Bounding quantum-gravity-inspired decoherence using atom interferometry

PRA: Fundamental concepts

on 2016-12-12 3:00pm GMT

Author(s): Jiří Minář, Pavel Sekatski, and Nicolas Sangouard

Hypothetical models have been proposed in which explicit collapse mechanisms prevent the superposition principle from holding at large scales. In particular, the model introduced by Ellis et al. [J. Ellis et al.Phys. Lett. B 221, 113 (1989)] suggests that quantum gravity might be responsible for …

 

[Phys. Rev. A 94, 062111] Published Mon Dec 12, 2016

 

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