Foundations of Physics最新文献

The polarization,magnetization and conductivity features of a conductor polarizable and magnetizable medium are described by a continuum collection of the antisymmetric tensor fields and a continuum collection of the vector fields in the Minkowski’s space-time. The conservation principle of the energy-momentum four-vector of the total system is provided in a fully canonical approach. The conservation principle of the energy-momentum four-vector of the total system gives the force four-vector on the free external charges moving in the conductor magneto-dielectric medium. The total classical relativistic Cherenkov’s radiation power emerged by a charged particle uniformly moving inside the medium is calculated. The quantum relativistic Cherenkov’s radiation power of a charged particle moving inside a homogeneous conductor magneto-dielectric medium is calculated by two methods. In the first method the motion of the charged particle is described by the relativistic quantum mechanics. The quantum relativistic Cherenkov’s radiation power of the charged particle moving in the medium is calculated in the initial state that the charged particle is in a very sharp normalized distribution in the momentum space and the quantum relativistic fields describing the medium are in the vacuum states. In the second approach the motion of an electron moving in the medium is described by the quantum relativistic Dirac’s field. The quantum relativistic Cherenkov’s radiation power of the electron moving in the medium is computed in the initial state that the quantum relativistic Dirac’s field is contained an electron with a definite spin and a very sharp normalized distribution in the momentum space and the quantum relativistic dynamical fields modeling the medium are in the vacuum states. The two methods of the calculation of the quantum relativistic Cherenkov’s radiation power of the electron moving inside the conductor magneto-dielectric medium are compared.

In this short paper, we propose a new framework for obtaining basic aspects of quantum mechanics that originate from estimating the mean value of the position of a statistical system based on the generalized Bayes estimators. We show that while the first-order estimation leads to a classical system, the second-order estimation produces the time-independent Schrödinger equation. The Born rule describes the probabilistic nature of quantum particles, and Max Born postulated it independently from the Schrödinger equation. We show that under the proposed model, both the Schrödinger equation and the Born rule are captured organically; particularly, we show that the Born rule leads to the Schrödinger equation. Finally, we show how the proposed model deals with the transition from quantum mechanics into classical mechanics when dealing with macroscopic objects without external assumptions.

The electron’s spin magnetic moment is ordinarily described as anomalous in comparison to what one would expect from the Dirac equation. But, what exactly should one expect from the Dirac equation? The standard answer would be the Bohr magneton, which is a simple estimate of the electron’s spin magnetic moment that can be derived from the Dirac equation either by taking the non-relativistic limit to arrive at the Pauli equation or by examining the Gordon decomposition of the electron’s current density. However, these derivations ignore two effects that are central to quantum field theoretic calculations of the electron’s magnetic moment: self-interaction and mass renormalization. Those two effects can and should be incorporated when analyzing the Dirac equation, to better isolate the distinctive improvements of quantum field theory. Either of the two aforementioned derivations can be modified accordingly. Doing so yields a magnetic moment that depends on the electron’s state (even among z-spin up states). This poses a puzzle for future research: How does the move to quantum field theory take you from a state-dependent magnetic moment to a fixed magnetic moment?

The problem of recovering information from the interior of a black hole is crucial to any resolution of the information loss paradox. In this article, we critically evaluate the program of holographic interior reconstruction within the AdS/CFT correspondence, explaining the conceptual underpinnings and implicit assumptions behind the recovery of black hole interior information, in the face of the apparent impossibility of doing so due to the AMPSS paradox. We also show how the implicit assumptions behind holographic interior reconstruction are the same as those underpinning an apparently unrelated popular resolution of the firewall paradox. By doing so, we highlight how holographic interior reconstruction fits within a larger conceptual strategy for attacking the problem of describing black holes in Quantum Gravity.

It is proposed that measurement devices can be modelled to have an open decoherence dynamics that is faster than any other relevant timescale, which is referred to as the ultradecoherence limit. In this limit, the measurement device always assumes a definite state upto the accuracy set by the fast decoherence timescale. Further, it is shown that the clicking rate of measurement devices can be derived from its underlying parameters, not only for the von Neumann ideal measurement devices but also for photon detectors in equal footing. This study offers a glimpse into the intriguing physics of measurement processes in quantum mechanics, with many aspects open for further investigation.

In order to reconcile the entropy reduction of a system through external interventions that are linked to a measurement with the second law of thermodynamics, there are two main proposals: (i) The entropy reduction is compensated by the entropy increase as a result of the measurement on the system (“Szilard principle"). (ii) The entropy reduction is compensated by the entropy increase as a result of the erasure of the measurement results (“Landauer/Bennett principle"). It seems that the LB principle is widely accepted in the scientific debate. In contrast, in this paper we argue for a modified S principle and criticize the LB principle with regard to various points. Our approach is based on the concept of “conditional action", which is developed in detail. To illustrate our theses, we consider the entropy balance of a variant of the well-known Szilard engine, understood as a classical mechanical system.

It is widely accepted that the states of any quantum system are vectors in a Hilbert space. Not everyone agrees, however. The recent paper “The unphysicality of Hilbert spaces” by Carcassi, Calderón and Aidala is a thoughtful dissection of the mathematical structure of quantum mechanics that seeks to pinpoint supposedly unsurmountable difficulties inherent in postulating that the physical states are elements of a Hilbert space. Its pivotal charge against Hilbert spaces is that by a change of variables, which is a change-of-basis unitary transformation, one “can map states with finite expectation values to those with infinite ones”. In the present work it is shown that this statement is incorrect and the source of the error is spotted. In consequence, the purported example of a time evolution that makes “the expectation value oscillate from finite to infinite in finite time” is also faulty, and the assertion that Hilbert spaces “turn a potential infinity into an actual infinity” is unsubstantiated. Two other objections to Hilbert spaces on physical grounds, both technically correct, are the isomorphism of separable Hilbert spaces and the unavoidable existence of infinite-expectation-value states. The former turns out to be quite irrrelevant but the latter remains an issue without a fully satisfactory solution, although the evidence so far is that it is physically innocuous. All in all, while the authors’ thesis that Hilbert spaces must be given up deserves some attention, it is a long way from being persuasive as it is founded chiefly on a misconception and, subsidiarily, on immaterial or flimsy arguments.

We introduce a non-Hermitian operator, and then, we discuss the possibility of finding an Aharonov-Bohm-type effect and persistent currents at zero temperature. This non-Hermitian operator is (mathcal{P}mathcal{T})-symmetric. Further, we study the Aharonov-Bohm-type effect and persistent currents at zero temperature in this (mathcal{P}mathcal{T})-symmetric quantum system in a rotating reference frame.

This study introduces the quantum force wave equation (QFWE) as a general theory of quantum forces (GToQF), a novel framework that redefines quantum forces as emergent phenomena arising from the interaction between quantum particles and curved spacetime. By coupling wave functions to spacetime curvature and gauge fields, the theory establishes a dynamic, bidirectional relationship between quantum states and spacetime geometry. This approach provides a unified description of quantum forces in highly curved and dynamic gravitational fields, extending beyond the limitations of existing theories. The theory offers fresh insights into quantum gravity, quantum field theory in curved spacetime, and particle physics in extreme conditions, serving as a versatile tool for exploring the interplay between quantum mechanics and spacetime structure. This work lays the foundation for the advancement of high-energy physics and cosmology in regimes where spacetime curvature is fundamental.

We explore the dynamical behavior of two f(T, B) gravity models with a scalar field: 1. (f(T,B)=T-gamma logbigg [frac{psi B_{0}}{B}bigg ]) and 2. (f(T,B)=eta T+frac{zeta }{B^{n}}), using the potential (V(phi )=V_{0}(alpha +e^{-beta phi })^{-delta }) and an interaction term (bar{Q} = epsilon H dot{phi }^2). A phase space analysis reveals four fixed points in Model 3.1 (three stable, one saddle) and five in Model 3.2 (four stable), indicating transitions from matter to dark energy dominance. With interaction, Model 3.2 exhibits seven fixed points, including five stable, one unstable (stiff matter era) and one saddle point. Evolution of the deceleration parameter q and the total EoS parameter (omega _{tot}) confirms sustained cosmic acceleration, with present values (q_{0} = -1.005) and (omega _{0} = -0.556) (Model 3.1) and (q_{0} = -1.245) and (omega _{0}=-1.0404) (Model 3.2). Comparisons of our observationally constrained parameters with (Lambda )CDM show strong consistency, supporting the viability of these models in describing the late-time accelerated expansion of the Universe.