相关论文: Influence of the cosmological constant on $\kappa$…
We construct and analyze a model of the neutron star in the k deformed space-time. This is done by first deriving the k deformed generalization of the Einstein tensor, starting from the non-commutative generalization of the metric tensor.…
Regarding a $d-$dimensional spherically symmetric line element in the context of Einstein-$\Lambda$ gravity, the hydrostatic equilibrium equation of stars is obtained. Then, by using the lowest order constrained variational (LOCV) method…
In this paper, we investigate the structure of neutron stars by considering both the effects of the cosmological constant and the existence of quark matter for neutron stars in Einstein's gravity. For this purpose, we use a suitable…
We present a systematic investigation of the cosmological constant effects in compact stars interiors in the framework of Einstein's gravity. Consideration of a cosmological constant $\Lambda$ in compact stars is motivated by the mechanism…
We derive the equation for pressure within a neutron star, taking into account a non-zero cosmological constant ($\Lambda$). We then examine the stability of the neutron star's equilibrium state in the presence of cosmological constant. Our…
We derive bounds on the deformation parameter of the $\kappa$-spacetime by analyzing the effect of non-commutativity on astrophysical model. We study compact stars, taken to be degenerate Fermi gas, in non-commutative spacetime. Using tools…
In this paper we generalise core-envelope model of superdense star to a non-commutative space-time and study the modifications due to the existence of a minimal length, predicted by various approaches to quantum gravity. We first derive…
Considering space--time to be non-commutative, we study the evolution of the universe employing the approach of Newtonian cosmology. Generalizing the conservation of energy and the first law of thermodynamics to $\kappa$-deformed…
Physically based changes to general relativity (GR) often predict significant differences in how spacetime behaves near massive neutron stars. One of these modifications is represented by $f(\mathcal{Q}, { \mathcal{T}})$, with $\mathcal{Q}$…
The relativistic equations of hydrostatic equilibrium for a spherically symmetric star, or the Tolman-Oppenheimer-Volkoff equations are known in higher dimensions. In this paper, these equations have been expressed in terms of parameters of…
We present the first numerical solutions of the coupled Einstein-Maxwell equations describing rapidly rotating neutron stars endowed with a magnetic field. These solutions are fully relativistic and self-consistent, all the effects of the…
We investigate the thermal Casimir effect for a massless scalar field in the curved spacetime of a neutron star within the Thermo Field Dynamics (TFD) formalism. Starting from the renormalized energy-momentum tensor, we generalize the…
There are now evidences that the cosmological constant $\Lambda$ has a non-zero positive value. Alternative scenarios to a pure cosmological constant model are provided by quintessence, an effective negative pressure fluid permeating the…
In this letter we study the effects of a noncommutative in the phase space of an empty (4+1) Kaluza-Klein universe with cosmological constant. We analyze the effects of the noncommutative deformations on the cosmological constant. Finally…
Physics invites the idea that space contains energy whose gravitational effect approximates that of Einstein's cosmological constant, Lambda; nowadays the concept is termed dark energy or quintessence. Physics also suggests the dark energy…
The equation of state for the beta stable nuclear matter is calculated numerically, and then the Tolman-Oppenheimer-Volkov equation for the structure of the neutron star is solved in the fourth-order Runge-Kutta algorithm. It shows the mass…
In this work we present a modified TOV equation which incorporates the cosmological constant with regard to the recent astronomical observations that the Universe is in a phase of accelerated expansion. Using this modified TOV equation we…
We propose a time-varying cosmological constant with a fixed equation of state, which evolves mainly through its interaction with the background during most of the long history of the universe. However, such interaction does not exist in…
According to the general theory of relativity, a massive body induces curvature in the surrounding spacetime. In this study, the surface curvature (SC) of neutron stars is computed using various curvature quantities derived from the…
Photon mass and Cartan contortion bounds recently obtained from tiny Lorentz violation observations in cosmology are used to find a limit of ${\lambda}\le 10^{-4}{\alpha}$ for the massive photon-torsion dimensionless coupling. Here…