Annals of Physics最新文献

We construct a new solution in the Einstein–Maxwell-dilaton theory describing accelerating, charged, and rotating black hole, i.e. the accelerating Kaluza–Klein black hole. Some properties the spacetime are discussed, such as the electromagnetic fields, the area-temperature product, and the holography according to Kerr/CFT correspondence. As expected, the macroscopic Bekenstein–Hawking entropy for an extremal accelerating Kaluza–Klein black hole can be recovered by using Cardy formula of a two dimensional conformal field theory. An interesting feature is found, namely the area-temperature product is just the one belongs to the vacuum Einstein seed solution.

We set up the Wheeler–DeWitt (WDW) equation for late gravitational collapse. The fact that the gravitational collapse and the expanding/ collapsing universe can be described within the realm of the Robertson–Walker metric renders the corresponding WDW equation for collapsing matter a timeless Schrödinger equation. We explore the consequences of such an equation and find the density to be quantized in terms of the Planck density. Apart from that, the wave function as a solution of the WDW equation shows that the initial singularity is avoided. We concentrate on different factor orderings in the kinetic term of the equation and show how after splitting off an exponential ansatz, new polynomials entering the solution can be constructed. This enables us to conclude that the factor ordering changes the details of the solution and interpretation, but overall on a qualitative level the results remain the same. We also probe into the effects of a positive cosmological constant. It offers the possibility of a tunneling scenario at the cosmological horizon.

This paper aims to investigate the Landau problem in the framework of a two-dimensional dynamical noncommutative (DNC) space. We study the deformed Landau problem using time-independent perturbation theory, wherein the energy shift notably depends on the DNC parameter $\tau$. Using the accuracy of energy measurement, we put an upper bound on the parameter $\tau$. Moreover, we study magnetoconductivity by employing the Kubo formula. This approach has allowed us to test the effects of noncommutative and DNC spaces on the behavior of magnetoconductivity. We show that dynamical noncommutativity of space has no effects on the x-component of the magnetoconductivity, but has a direct effect on its y-component.

In a recent paper, we studied a modified version of the Einstein–Rosen bridge. This modified bridge is traversable and works as a one-way membrane: a particle on the first sheet falling towards the throat will reach it in finite time (in Eddington coordinates), and will continue its trajectory on the second sheet. In this paper, we show that the particle undergoes a PT-symmetry as it crosses the throat. This could lead to observable effects thanks to an additional ingredient proposed by Einstein and Rosen: congruent points on the two sheets are identified. We propose a bimetric model to realize this identification for our modified bridge

The deviation of the decay law from the exponential is a well known effect of quantum mechanics. Here we analyze the relativistic survival probabilities, $S(t,p)$, where $p$ is the momentum of the decaying particle and provide analytical expressions for $S(t,p)$ in the exponential (E) as well as the nonexponential (NE) regions at small and large times. Under minimal assumptions on the spectral density function, analytical expressions for the critical times of transition from the NE to the E at small times and the E to NE at large times are derived. The dependence of the decay law on the relativistic Lorentz factor, $\gamma =1/\sqrt{1-v^2/c^2}$, reveals several interesting features. In the short time regime of the decay law, the critical time, ${\tau }_{st}$, shows a steady increase with $\gamma$, thus implying a larger NE region for particles decaying in flight. Comparing $S(t,p)$ with the well known time dilation formula, $e^{-\Gamma t/\gamma }$, in the exponential region, an expression for the critical $\gamma$ where $S(t,p)$ deviates most from $e^{-\Gamma t/\gamma }$ is presented. This is a purely quantum correction. Under particular conditions on the resonance parameters, there also exists a critical $\gamma$ at large times which decides if the NE region shifts backward or forward in time as compared to that for a particle at rest. All the above analytical results are supported by calculations involving realistic decays of hadrons and leptons.

In this investigation, we perform an observational statistical analysis in the theory of $f(R,L_m)$ gravity. The proposed theoretical model is based on the Ricci scalar’s non-linear contribution. We use a distinct parametrization for the deceleration parameter and constrain the model parameters by using various observational data. To determine the best-fit model for the cosmological parameters, we use different observational datasets such as the Hubble Space Telescope, the Pantheon Supernova Survey, the Gold dataset, the Gamma-Ray Burst (GRB), and the Baryon Acoustic Oscillations (BAO). Furthermore, we study the late-time cosmic evolution of the Universe in detail and examine the implications of the constraint values on cosmological parameters. Additionally, we conduct a thorough comparison with the standard cosmological model $\Lambda$CDM and other standard models obtained by Odintsov et al. (2024); Odintsov et al. (2023) to examine the validity of our proposed model in the low-redshift regimes. Finally, we find that the proposed model encapsulates an intriguing transition from early deceleration at high redshift to acceleration at low redshift, a quintessence dark energy scenario, and convergence towards the well-established $\Lambda$CDM model in late-time Universe’s evolution.

The Stokes–Mueller method is used to analyze the scattering of entangled photon pairs in a two-photon system. This study examines the scenario where one of the photons, part of a pair of maximally entangled annihilation photons, undergoes intermediate Compton scattering before both photons are detected using Compton polarimeters. The method also accounts for potential quantum-decoherence effects resulting from Compton scattering. The analysis investigates the scattering behavior in both parallel and perpendicular planes, identifying variations in the modulation factor that affect azimuthal correlations. These variations include increases, decreases, sign changes, or disappearances at certain intermediate scattering angles. This work aims to provide theoretical results that support the testing and verification of predictions made by quantum field theory.

A reciprocality between the statistical variance of observables of a thermodynamic state and that of their conjugate variables, as entropic forces, originates from the thermodynamic conjugacy with respect to an entropy function. This thermodynamic uncertainty principle in equilibrium can be derived from the Maximum Entropy principle and is independent upon underlying mechanistic details. We present, based on the Maximum Caliber principle as the dynamic generalization of Maximum Entropy, the formalism of the uncertainty principle in kinetics in time homogeneous Markov processes between transitional observables and their conjugate path entropic forces. A stochastic biophysical model for molecular motors is used as an illustrating example. The present work generalizes the phenomenological thermodynamics of uncertainties/fluctuations and is applicable to data ad infinitum.

This work presents a new static and spherically symmetric traversable wormhole solution in General Relativity, which is supported by the quantum vacuum fluctuations associated with the Casimir effect of the Yang–Mills field confined between perfect chromometallic mirrors in $(3+1)$ dimensions, recently fitted using first-principle numerical simulations. Initially, we employ a perturbative approach for $x=mr\ll 1$, where $m$ represents the Casimir mass and $r$ is the radial coordinate. This approach has proven to be a reasonable approximation when compared with the exact case in this regime. To find well-behaved redshift functions, we impose constraints on the free parameters. As expected, this solution recovers the electromagnetic-like Casimir solution for $m=0$. Analyzing the traversability conditions, we graphically find that all are satisfied for $0\le m\le 0.17$. On the other hand, all the energy conditions are violated, as usual in this context due to the quantum origin of the source. Stability from Tolman–Oppenheimer–Volkov (TOV) equation is guaranteed for all $r$ and from the speed of sound for $0.16\le m\le 0.18$. Therefore, for $0.16\le m\le 0.17$, we will have a stable solution that satisfies all traversability conditions.

Our study employs the nuclear shell model to systematically compute the half-lives of $\beta$-decay for nuclei in the mass range of $A=18-39$, encompassing the majority of $sd$ shell nuclei. This analysis utilizes the USDB and SDNN Hamiltonians. The theoretical outcomes contain calculations of various parameters such as $Q$-values, half-lives, excitation energy, log$ft$ values, and branching ratios. We explore these results with axial–vector coupling constant for weak interactions, denoted as $g_A$ $(=1.27)$, and $\kappa$ value $(=6289)$. We perform calculations of Gamow Teller matrix elements for 116 decay processes to calculate the quenching factor; we found a quenching factor of $q=0.794\pm 0.05$ for the USDB interaction and $q=0.815\pm 0.04$ for the SDNN interaction. We have also calculated superallowed transitions $0^{+}\to 0^{+}$ for seven nuclei. Further, we have also included the electron capture phase space factor for the required nuclei to calculate the half-lives. This inclusion leads to small contribution in results, particularly for nuclei where electron capture (EC) plays a significant role. The overall results are in agreement with the experimental data.