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.
Testing theories of Gravity and Supergravity with inflation and observations of the cosmic microwave background. (arXiv:1607.06325v1 [astro-ph.CO])
Many extensions of Einstein’s theory of gravity have been studied and proposed with various motivations like the quest for a quantum theory of gravity to extensions of anomalies in observations at the solar system, galactic and cosmological scales. These extensions include adding higher powers of Ricci curvature $R$, coupling the Ricci curvature with scalar fields and generalized functions of $R$. In addition when viewed from the perspective of Supergravity (SUGRA) many of these theories may originate from the same SUGRA theory interpreted in different frames. SUGRA therefore serves as a good framework for organizing and generalizing theories of gravity beyond General Relativity. All these theories when applied to inflation (a rapid expansion of early Universe in which primordial gravitational waves might be generated and might still be detectable by the imprint they left or by the ripples that persist today) can have distinct signatures in the Cosmic Microwave Background radiation temperature and polarization anisotropies. In this review we give a detailed discussion on the standard model of cosmology ($\Lambda$CDM), inflation and cosmological perturbation theory. We survey the theories of gravity beyond Einstein’s General Relativity, specially which arise from SUGRA, and study the consequences of these theories in the context of inflation and put bounds on the theories and the parameters therein from the observational experiments like Planck, Keck/BICEP. The possibility of testing these theories in the near future in CMB observations and new data coming from colliders like the LHC, provides an unique opportunity for constructing verifiable models of particle physics and General Relativity.
Authors: Subhash Kak
This paper presents an epistemological perspective on quantum communication between parties that highlights the choices that must be made in order to send and obtain information. The notion of information obtained in such a communication is a property associated with the observers and while dependent on the nature of the physical system its fundamental basis is epistemic. We argue that the observation process is in accord with the principle of psychophysical parallelism that was used by Bohr, von Neumann, Schrodinger and others to establish the philosophical basis of complementarity but has since fallen out of fashion. This principle gave coherence to the original Copenhagen Interpretation without which the latter has come to have some sort of an ad hoc character.
Further Considerations Regarding the Aharonov-Bohm Effect and the Wavefunction of the Entire System. (arXiv:1607.06419v1 [quant-ph])
Authors: Allan Walstad
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.
Authors: Isaak Mayergoyz
During measurements, appreciable amplification (enhancement) of microscopic effects occur to make them tangible to a macroscopic observer. Such amplification may be caused by instabilities involved in a measurement process. It is demonstrated that these instabilities may result in random branching of deterministic dynamics which may lead to random wave function collapse. In the case of two level systems, the Born probability rule emerges as the simplest linear solution to the equation for measurement probabilities.
Authors: Allan Walstad
This paper undertakes a critical reexamination of the electrostatic version of the Aharonov-Bohm (“AB”) effect. The conclusions are as follows: 1. Aharonov and Bohm’s 1959 exposition is invalid because it does not consider the wavefunction of the entire system, including the source of electrostatic potential. 2. As originally proposed, the electrostatic AB effect does not exist. Perhaps surprisingly, this conclusion holds despite the relativistic covariance of the electromagnetic four-potential combined with the well-established magnetic AB effect. 3. Although the authors attempted, in a 1961 paper, to demonstrate that consideration of the entire system would not change their result, they inadvertently assumed the desired outcome in their analysis. 4. Claimed observations of the electrostatic AB effect or an analogue thereof are shown to be mistaken.
Derivation of a time dependent Schr\”odinger equation as quantum mechanical Landau-Lifshitz-Bloch equation. (arXiv:1607.06184v1 [cond-mat.mes-hall])
Authors: Robert Wieser
The derivation of the time dependent Schr\”odinger equation with transversal and longitudinal relaxation, as the quantum mechanical analog of the classical Landau-Lifshitz-Bloch equation, has been described. Starting from the classical Landau-Lifshitz-Bloch equation the transition to quantum mechanics has been performed and the corresponding von-Neumann equation deduced. In a second step the time Schr\”odinger equation has been derived. Analytical proofs and computer simulations show the correctness and applicability of the derived Schr\”odinger equation.