Modern Physics Letters A

In the framework of electroweak theory and perturbative quantum chromodynamics, we examine various exclusive decay channels of $W$ bosons that can be fully or partially reconstructed. Our findings provide predictions for the partial widths and address some gaps in previous literature. We also place a strong emphasis on understanding and estimating the associated theoretical uncertainties.

In this work, we have discussed about a rotating gravastar model and some physical aspects in the presence of an anisotropic fluid source in the framework of General Relativity. We have considered two cases: one is gravastar’s interior fluid rigidly (or slowly) rotates, and the other is gravastar’s interior fluid non-rigidly rotates. We have considered a gravastar with three regions: interior region, thin shell region, and exterior region. We have written the field equations for a spherically symmetric object in which interior fluid rigidly (or slowly) rotates with angular velocity ($\omega$). Next, we have solved the field equations in three regions of a gravastar. To compute the analytical solution within the shell region, we have used the approximation $e^{-\lambda }=h\ll 1$. Some physical quantities, like the proper length of the thin shell, energy, and entropy within the shell, have been obtained and discussed graphically. We have evaluated the surface energy density and the surface pressure analytically through the junction conditions between the surfaces of the interior and exterior regions. Next, we have discussed the equation of state parameter of the surface layer, the mass of the thin shell, and the total mass of the gravastar analytically and graphically. Also, we have discussed the stable region of such type gravastar. Again, we constructed the field equations for a spherically symmetric object in which interior fluid rotates non-rigidly. Next, we have discussed these field equations for a gravastar with three regions. Also, we have obtained some physical quantities like the proper length of the thin shell region, energy, entropy, density and angular velocity within the shell region for such type of gravastar. The stability has been discussed through the surface redshift within the shell region, and we get our model stable and physically valid.

In this paper, we consider a charged relativistic spin-1 oscillator under the influence of an internal magnetic flux in a $(2+1)$-dimensional spacetime induced by a spinning point source. In order to analyze the effects of the internal magnetic flux and spin of the point source on the relativistic dynamics of such a vector field, we seek a non-perturbative solution of the associated spin-1 equation derived as an excited state of Zitterbewegung. By performing an analytical solution of the resulting equation, we determine exact results for the system in question. Accordingly, we analyze the effects of spin of the point source and internal magnetic flux on the relativistic dynamics of the considered test field. We see that the spin of such a field can be altered by the magnetic flux and this means that the considered system may behave as a fermion or boson according to the varying values of the magnetic flux, in principle. We observe that the internal magnetic flux and the spin of the point source impact on the relativistic energy levels and probability density functions. Also, our results indicate that the spin of the point source breaks the symmetry of the energy levels corresponding to particle–antiparticle states.

In this paper, we study two different dynamic structures of holographic dark energy, namely Tsallis and Kaniadakis, within the framework of Brans–Dicke cosmology. We consider the complex form of the quintessence model and examine both non-interacting and interacting cases, calculating various cosmological parameters such as the equation of state $\omega$ and discussing the behavior of $\omega -{\omega }^{\prime }$. We modify the potential and study the scalar field dynamics of complex quintessence cosmology. Additionally, we examine the effects of the two parts of the quintessence field (real and complex) and the fractional energy density ${\mathrm{\Omega }}_D$, determining whether they can describe a real universe. We note that the fractional energy density cannot be arbitrary between 0 and 1, as it depends on the Tsallis, Kaniadakis and Brans–Dicke cosmology-free parameters. For each model, we establish a relationship between the fractional energy density and other parameters such as $\delta$, $b^2$, $\alpha$ and $\beta$.

In this paper, we discuss a mode sum regularization method for the self-force acting on a charged test particle moving around a Banados, Teitelboim and Zanelli (BTZ) black hole. First, we have calculated the self-force on each individual mode. Then we evaluated our result by summing up the contribution on each mode. We studied a general scheme for static black holes and then present the result for radial trajectories around $(2+1)$-dimensional charged BTZ black hole in Einstein–Gauss–Bonnet (EGB) gravity. We find that the parameter which is coupling ($2+1$) GR to Einstein–Gauss–Bonnet gravity has a significant impact on the self-force.

We study phonon modes associated with magnetic vortex lattices of finite isospin chiral perturbation theory near the upper critical point by introducing quasimomentum fluctuations to the lattice and calculate dispersion relations associated with the optical and acoustic modes. We find that one of the acoustic modes is massless and that its energy for small transverse quasimomentum is quartic (due the presence of an isospin chemical potential), which is significantly softer than the “supersoft” (quadratic) massless mode of the Abelian Higgs Model (AHM). Due to the presence of derivative interactions, which is absent in the AHM, the speed of the longitudinal mode depends on both the isospin chemical potential and the external magnetic field. Our results suggest that the standard assumption of an ordered lattice in finite isospin QCD should be revisited and the existence of a disordered spaghetti phase of a vortex liquid or gas, should be considered.

At large-scale distances where the space-time is curved due to gravity, a nonzero minimal uncertainty in the momentum, ${(\mathrm{\Delta }P)}_{min}$, is being estimated to emerge. The presence of minimal uncertainty in momentum allows a modification to the quantum uncertainty principle, which is known as the extended uncertainty principle (EUP). In this work, we handle the harmonic oscillator problem in the EUP scenario and obtain analytical exact solutions in classical and semi-classical domains. In the classical context, we establish the equations of motion of the oscillator and show that the EUP-corrected frequency is depending on the energy and deformation parameter. In the semi-classical domain, we derive the energy eigenvalue levels and demonstrate that the energy spectrum depends on $n^2$, as the feature of hard confinement. Finally, we investigate the impact of the EUP on the harmonic oscillator’s thermodynamic properties by using the EUP-corrected partition functions in the classical limit in the (A)dS backgrounds.

An addendum for one hidden issue in manuscript “Signature-causality reflection generated by Abelian gauge transformations” is outlined.