In this paper we examine asymptotically anti de Sitter rotating black string solutions of four-dimensional Einsteinian cubic gravity in the presence of nonlinear Born-Infeld electrodynamics. By assuming that the solutions are completely regular at the horizon and studying the asymptotic and near-horizon behavior of the solutions, we compute independently the Hawking temperature, the Wald entropy, the mass, the angular momentum, the charge and the electrostatic potential, and show that the first law of thermodynamics for rotating black strings with non-linear Born-Infeld source holds exactly in Einsteinian cubic gravity. We also show that when the nonlinear parameter goes to infinity, the solutions tend to those obtained from Maxwell’s electrodynamics

In this paper, we consider the four-dimensional electrodynamics with SIM(2) symmetry in a very special relativity framework. First, we examine the charge-conjugation symmetry of the action at the tree (classical) level and show that the action in this framework is charge-conjugation invariant. Then, to investigate perturbatively the preservation of charge-conjugation symmetry at the loop (quantum) level, we shall focus on one-loop graphs with an odd number of photon external lines. To this end, we use the effective action approach to obtain the general form of the photon odd-point function and study the behavior of the one and three-point function of the photon under the charge-conjugation transformation. Our analysis shows that the total amplitude of the one and three-point function vanishes and hence the charge-conjugation symmetry is preserved at the quantum level. Next, we use a non-perturbative method to show that this symmetry exists at the quantum level (to all orders) and the total amplitude of all photon's odd-point functions vanishes.

In this paper, we obtain a new class of $(n+1)$-dimensional magnetic brane solutions of quasi-topological gravity in the presence of exponential and logarithmic nonlinear electrodynamics by a spinning magnetic branes with one or more rotation parameters. For the spinning brane, the brane has a net electric charge, when one or more rotation are non zero, and also this electric charge is proportional to the magnitude of the rotation parameter. However, when all the rotation parameters are zero (static brane), the electric field vanishes and the brane has no net electric charge. In the class of solutions, we have a spacetime with an angular magnetic field. These solutions are horizonless and have no curvature, but there is a conic singularity with a deficit angle. In addition, these two forms of nonlinear electrodynamics theory, have the same behaviors for the obtained solutions. Finally, we use the counterterm method and compute conserved quantities of these spacetimes.

In this paper, by considering a system consisting of a single two-level trapped ion interacting with a single-mode quantized radiation field inside a lossless cavity, the temporal evolution of the ionic and the cavity-field quantum statistical properties including photon-counting statistics, quantum fluctuations of the field quadratures and quantum fluctuations of the ionic dipole variables are investigated. It is found that in the Lamb-Dicke limit it is possible for the cavity-field to evolve into a non classical state (squeezed state or state with sub-Poissonian statistics) and this possibility is solely affected by the internal and external quantum dynamics of the ion. Also it is found that the dipole squeezing may occur in the dynamics of the trapped ion which sensitively depends on quantum statistics of the cavity-field.

In this study, the exact black hole (BH) solutions of Brans-Dicke (BD) theory were obtained under the influence of power-Maxwell nonlinear electrodynamics. Since the Jordan frame field equations are highly nonlinear, they cannot be solved directly. Using the conformal transformations, we translated them to the Einstein frame, where the field equations are decupled, and the theory is the well-known Einstein-dilaton (Ed) gravity. Through solving the equations, three novel classes of Ed-power-Maxwell BHs were introduced. After calculating the thermodynamic quantities, using the appropriate approaches, we showed that the first law of BH thermodynamics is valid in the Einstein frame. Also, thermal stability of the BHs was analyzed using the canonical ensemble method. The exact BH solutions of BD-power-Maxwell theory were obtained from their Einstein correspondence by applying the inverse conformal transformations. We showed that thermodynamic quantities remain invariant under conformal transformations. As the result, thermodynamical first law is valid for the Jordan frame BHs and, their thermal stability properties are just like those of Einstein frame.

In this paper, a higher-derivative model for electrodynamics is presented in a D+1 dimensional Minkowski space-time by introducing a form factor into the kinetic term of Maxwell theory as -1/4µ0 FµνFµν→ -1/4µ0 FµνFHD2(ℓ2□)Fµν , where is a characteristic length scale. Our calculations show that for DÊÎ{3, 4, 5} the electrostatic potential of a point charge is finite at the position of the point charge in this higher-derivative modification of Maxwell's theory. For D=3 the explicit form of the potential and the electric field of a point charge are obtained analytically in this higher-derivative electrodynamics. According to numerical estimations, the upper bound for the characteristic length scale ℓ is ℓmax ~1/100ℓelectroweak , where ℓelectroweak= 10-18m is the electroweak length scale. Finally, it should be emphasized that for ℓ<<1 the results of this paper are compatible with the results of ordinary Maxwell theory.

The dynamic responses of membrane are completely dependent on Pre-tensioned forces which are applied over a boundary of arbitrary curvilinear shape. In most practical cases, the dynamic responses of membrane structures are undesirable. Whilst they can be designed as vibration-based energy harvesters. In this paper a smart flat membrane sheet (SFMS) model for vibration-based energy harvester is proposed. The SFMS is made of an orthotropic polyvinylidene fluoride (PVDF) flat layer that has piezoelectricity effect. For this aim, polarization vector of PVDF layer is considered parallel to the applied electric field intensity vector. Electrodynamics governing equations of transverse motion of SFMS including active and modified pre-tensioned force are exploited. Transverse displacement component is expanded by the separable form corresponding to the axial and transverse and the linear ODE of motion based on generalized shape coefficients is obtained using Galerkin method. Finally, the explicit relation between forced vibration of SFMS and current and voltage harvesting are obtained. Numerical energy harvesting analyses were developed for an orthotropic rectangle SFMS and the voltage as function of the time is calculated based on different resistances. Parametric simulation shows a 1 m length and 0. 5 width SFMS has ability to produce a peak to peak voltage about of 30 mV.

A time-like unit vector field is used to generalize Einstein's gravity. The resulting theory, called the Einstein-aether theory, consists of a minimal coupling between an aether field and gravity. Inspired by the Bopp-Podolsky electrodynamics, which is well-known for removing the singularity at the point charge, we generalized the Einstein-aether theory by adding such a higher order self-interaction term. We show that the resulting theory can explain the late time accelerated expansion of the universe. We then consider the cosmological perturbation theory on the top of the de Sitter solution and try to answer the question whether an additional Lorentz breaking vector field can cure the small scales instability of the Bopp-Podolsky electrodynamics.

In this paper, we investigate the effect of the motion of a magnetodielectric particle on the quantum thermodynamic properties of a system. Specifically, we study the behavior of a polarizable and magnetizable dielectric particle moving above a semi-infinite bulk dielectric in the presence of an electromagnetic field. Using a microscopic approach, we propose a covariant Lagrangian for the combined system and obtain a dynamical covariant response of the moving particle. We calculate the emitted power from the work extracted by the electric and magnetic dipoles of the moving particle. We explicitly determine the behavior of the main thermodynamic functions of the system, including thermal correlation functions, free energy, mean energy, entropy, and heat capacity. It is found that the thermodynamic properties of the moving particle in the electromagnetic field depend on the properties of the semi-infinite bulk dielectric. Moreover, we demonstrate that the formulation of quantum thermodynamics for an electromagnetic system in uniform relative motion differs from its formulation in the rest-frame.

In this article, we want to describe the phenomenon of one-dimensional blackbody radiation by using the theory of quantum electrodynamics and the theory of open quantum systems in Heisenberg's picture. For this purpose, we consider a Fabry-Perot cavity, which is in thermal equilibrium with its environment at a certain temperature, while one of its longitudinal modes is optically pumped by an external laser. By writing the Heisenberg-Lanjevin dynamical equations for the longitudinal modes inside the cavity and solving them, we obtain the time evolution of the internal optical field in the steady state. Then, using the input-output theory in quantum optics, we obtain the optical field of the cavity output in the steady state and calculate the power spectrum of the cavity output from that. The result appears as the sum of a coherent part and an incoherent part in the output power spectrum, where the former is related to the mean field and the latter is related to the quantum fluctuations of the field inside the cavity, which is the source of thermal radiation. Finally, we show that in the continuum limit, the quantum fluctuations of the cavity output lead to the emergence of the one-dimensional Planck spectrum, which at the low-frequency limit leads to the one-dimensional form of the Rayleigh-Jeans relation. Then, by calculating the total output energy density, we obtain the Stefan-Boltzmann law for one-dimensional blackbody radiation