# Weekly Papers on Quantum Foundations (40)

Gauge Is More Than Mathematical Redundancy

ROVELLI, Carlo (2020) Gauge Is More Than Mathematical Redundancy. [Preprint]

Measurement and Quantum Dynamics in the Minimal Modal Interpretation of Quantum Theory

Barandes, Jacob A. and Kagan, David (2020) Measurement and Quantum Dynamics in the Minimal Modal Interpretation of Quantum Theory. Foundations of Physics, 50 (10). pp. 1189-1218.

A New Perspective On Time And Physical Laws

James, Lucy (2020) A New Perspective On Time And Physical Laws. [Preprint]

Quantum probability’s algebraic origin

Niestegge, Gerd (2020) Quantum probability’s algebraic origin. [Preprint]

Learning Entropy Production via Neural Networks

Author(s): Dong-Kyum Kim, Youngkyoung Bae, Sangyun Lee, and Hawoong Jeong

This Letter presents a neural estimator for entropy production (NEEP), that estimates entropy production (EP) from trajectories of relevant variables without detailed information on the system dynamics. For steady state, we rigorously prove that the estimator, which can be built up from different ch…

[Phys. Rev. Lett. 125, 140604] Published Fri Oct 02, 2020

The Vienna Delayed-Choice Quantum Eraser Leaves No Choice. (arXiv:2010.00049v1 [quant-ph])

A realizable delayed-choice quantum eraser, using a modified Mach-Zehnder (MZ) interferometer and polarization entangled photons, is theoretically analyzed here. The signal photon goes through a modified MZ interferometer, and the polarization of the idler photon provides path information for the signal photon. The setup is very similar to the delayed-choice quantum eraser experimentally studied by the Vienna group. It is demonstrated that in the class of quantum erasers with discrete output states, the delayed mode leaves no choice for the experimenter. The which-way information is always erased, and every detected signal photon fixes the polarization state of the idler, and thus gives information on precisely how the signal photon traversed the two paths. The analysis shows that the Vienna delayed-choice quantum eraser is the first experimental demonstration of the fact that the delayed mode leaves no choice for the experimenter, and the which-way information is always erased.

Gravity-Induced Geometric Phases and Entanglement in Spinors and Neutrinos: Gravitational Zeeman Effect. (arXiv:1802.10377v3 [gr-qc] UPDATED)

We show Zeeman-like splitting in the energy of spinors propagating in a background gravitational field, analogous to the spinors in an electromagnetic field, otherwise termed the Gravitational Zeeman Effect. These spinors are also found to acquire a geometric phase, in a similar way as they do in the presence of magnetic fields. However, in a gravitational background, the Aharonov-Bohm type effect, in addition to Berry-like phase, arises. Based on this result, we investigate geometric phases acquired by neutrinos propagating in a strong gravitational field. We also explore entanglement of neutrino states due to gravity, which could induce neutrino-antineutrino oscillation in the first place. We show that entangled states also acquire geometric phases which are determined by the relative strength between gravitational field and neutrino masses.

Time Evolution and Probability in Quantum Theory: The Central Role of Born’s Rule. (arXiv:2009.03435v2 [quant-ph] UPDATED)

In this treatise I introduce the time dependent Generalized Born’s Rule for the probabilities of quantum events, including conditional and consecutive probabilities, as the unique fundamental time evolution equation of quantum theory. Then these probabilities, computed from states and events, are to be compared with relative frequencies of observations. Schrodinger’s equation still is valid in one model of the axioms of quantum theory, which I call the Schrodinger model. However, the role of Schrodinger’s equation is auxiliary, since it serves to help compute the continuous temporal evolution of the probabilities given by the Generalized Born’s Rule. In other models, such as the Heisenberg model, the auxiliary equations are quite different, but the Generalized Born’s Rule is the same formula (covariance) and gives the same results (invariance). Also some aspects of the Schrodinger model are not found in the isomorphic Heisenberg model, and they therefore do not have any physical significance. One example of this is the infamous collapse of the quantum state. Other quantum phenomena, such as entanglement, are easy to analyze in terms of the Generalized Born’s Rule without any reference to the unnecessary concept of collapse. Finally, this leads to the possibility of quantum theory with other sorts of auxiliary equations instead of Schrodinger’s equation, and examples of this are given. Throughout this treatise the leit motif is the central importance of quantum probability and most especially of the simplifying role of the time dependent Generalized Born’s Rule in quantum theory.

Unveiling A Hidden Classical-Quantum Link. (arXiv:2009.08308v2 [quant-ph] UPDATED)

The conceptual divide between classical physics and quantum mechanics has not been satisfactorily bridged as yet. The purpose of this paper is to show that such a bridge exists naturally in the Green-Wolf complex scalar representation of electromagnetic fields and its extension to massive fields. The quantum mechanical theory of radiation that follows from the the Green-Wolf representation is applied to the cosmic microwave background radiation (CMBR) regarded as a universal medium, and the implications are explored.

Temperaturskalan och Boltzmanns konstant. (arXiv:2010.00470v1 [physics.hist-ph])

Authors: G.J. EhnholmM. Krusius

Temperature scale and the Boltzmann constant: The newest system of units is based on a compatible set of natural constants with fixed values. An example is the Boltzmann constant k which defines the thermal energy content kT. To express the base unit T, the absolute temperature in kelvin, an international agreement for the temperature scale is needed. The scale is defined using fixed points, which are temperatures of various phase transitions. Especially important has been the triple point of water at 273.1600 K. These fixed point temperatures determine the international temperature scale ITS within the Si system. Temperature measurement itself is based on physical laws and on the properties of appropriate thermometric materials selected to determine the temperature scale. For determining the Boltzmann constant, new precision techniques have been developed during the last two decades. Examples are different types of gas thermometry, which ultimately are based on the ideal gas law, and thermal noise of electric charge carriers in conductors. With these means it has become possible to fix the value of the Boltzmann constant with a relative uncertainty of < 1 ppm. As of 2019, the value of k has been agreed to be fixed at 1.380649×10^(-23) J/K. This agreement replaces the earlier definition of a Kelvin degree.

Universal constants and natural systems of units in a spacetime of arbitrary dimension. (arXiv:2005.08196v3 [gr-qc] UPDATED)

Authors: A. A. SheykinS. N. Manida

We study the properties of fundamental physical constants using the threefold classification of dimensional constants proposed by J.-M. L{\’e}vy-Leblond: constants of objects (masses, etc.), constants of phenomena (coupling constants), and “universal constants” (such as $c$ and $\hbar$). We show that all of the known “natural” systems of units contain at least one non-universal constant. We discuss the possible consequences of such non-universality, e.g., the dependence of some of these systems on the number of spatial dimensions. In the search for a “fully universal” system of units, we propose a set of constants that consists of $c$, $\hbar$, and a length parameter and discuss its origins and the connection to the possible kinematic groups discovered by L{\’e}vy-Leblond and Bacry. Finally, we give some comments about the interpretation of these constants.

The dynamical approach to spin-2 gravity

Publication date: Available online 28 September 2020

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

Author(s): Kian Salimkhani

Proca in the sky. (arXiv:2010.00513v1 [astro-ph.CO])

The standard model of cosmology, the $\Lambda$CDM model, describes the evolution of the Universe since the Big Bang with just a few parameters, six in its basic form. Despite being the simplest model, direct late-time measurements of the Hubble constant compared with the early-universe measurements result in the so-called $H_0$ tension. It is claimed that a late time resolution is predestined to fail when different cosmological probes are combined. In this work, we shake the ground of this belief with a very simple model. We show how, in the context of cubic vector Galileon models, the Hubble tension can naturally be relieved using a combination of CMB, BAO and SNe observations without using any prior on $H_0$ . The tension can be reduced even further by including the local measurement of the Hubble constant.

Can a nonextremal black hole be a particle accelerator?. (arXiv:2007.09413v2 [gr-qc] UPDATED)

Authors: O. B. Zaslavskii

We consider particle collisions in the background of a nonextremal black hole. Two particles fall from infinity, particle 1 is fine-tuned (critical), collision occurs in its turning point. The first example is the Reissner-Nordstr\”{o}m (RN) one. If the energy at infinity $E_{1}$ is big enough, the turning point is close to the horizon. Then, we derive a simple formula according to which $E_{c.m.}\sim E_{1}\kappa ^{-1/2}$, where $\kappa$ is a surface gravity. Thus significant growth of $E_{c.m.}$ is possible if (i) particle 1 is ultrarelativistic (if both particles are ultrarelativistic, this gives gain as compared to collisions in flat space-time), (ii) a black hole is near-extremal (small $\kappa$). In the scenario of multiple collisions the energy $E_{c.m.}$ is finite in each individual collision. However, it can grow in subsequent collisions, provided new near-critical particles are heavy enough. For neutral rotating black holes, in case (i) a turning point remains far from the horizon but large $E_{c.m.}$ is still possible. Case (ii) is similar to that for collisions in the RN metric. We develop a general theoretical scheme, direct astrophysical applications can be a next step to be studied.

A Principle Explanation of Bell State Entanglement: Conservation per No Preferred Reference Frame

Stuckey, W. M. and Silberstein, Michael (2020) A Principle Explanation of Bell State Entanglement: Conservation per No Preferred Reference Frame. In: UNSPECIFIED.

15 years of Nature Physics

Nature Physics, Published online: 01 October 2020; doi:10.1038/s41567-020-01051-9

Over the last 15 years, the content of Nature Physics has covered an enormous breadth of subjects at the forefront of physics. The journal’s past and present editors recount their favourite papers and what made chaperoning them to publication special.

Mind the gap

Nature Physics, Published online: 01 October 2020; doi:10.1038/s41567-020-01067-1

Mind the gap

Ising model for strings

Nature Physics, Published online: 01 October 2020; doi:10.1038/s41567-020-01065-3

Ising model for strings

INFORMATION-DEVOID ROUTES FOR SCALE-FREE NEURODYNAMICS

Tozzi, Arturo and Peters, James (2020) INFORMATION-DEVOID ROUTES FOR SCALE-FREE NEURODYNAMICS. [Preprint]

What does the world look like according to superdeterminism?

Le Bihan, Baptiste (2020) What does the world look like according to superdeterminism? [Preprint]

Inference to the Best Explanation and Norton’s Material Theory of Induction.

Davey, Kevin (2020) Inference to the Best Explanation and Norton’s Material Theory of Induction. [Preprint]

Answering Mermin’s challenge with conservation per no preferred reference frame

Stuckey, W. M. and Silberstein, Michael and McDevitt, Timothy and Le, T.D. (2020) Answering Mermin’s challenge with conservation per no preferred reference frame. Scientific Reports, 10 (15771).

The Role of Meta-Empirical Theory Assessment in the Acceptance of Atomism

Dawid, Richard (2020) The Role of Meta-Empirical Theory Assessment in the Acceptance of Atomism. [Preprint]

Gauge Invariance for Classical Massless Particles with Spin

Barandes, Jacob A. (2019) Gauge Invariance for Classical Massless Particles with Spin. [Preprint]