相关论文: Non-Singular Black Holes and mass inflation in mod…
We study an internal structure of (2+1)-dimensional black hole with the neutral scalar matter in the spherically symmetric geometry by using a quantum theory of gravity which holds in the both vicinities of the singularity and the apparent…
Black holes are the simplest objects in the universe. They correspond to extreme deformations of spacetime geometry, and can exist even devoid of matter. In general relativity, (electro)vacuum black holes are uniquely determined by their…
We study FRW cosmology for a non-linear modified F(R) Horava-Lifshitz gravity which has a viable convenient counterpart. A unified description of early-time inflation and late-time acceleration is possible in this theory, but the…
Infrared growth of geometrical fluctuations in inflationary spacetimes is investigated. The problem of gauge-invariant characterization of growth of perturbations, which is of interest also in other spacetimes such as black holes, is…
We study the effect of supergravity corrections due to a linear and a bilinear term in the K\"ahler potential, in the context of a supersymmetric hybrid inflation model. By appropriate choice of the parameters associated to these terms, we…
We investigate the stability of motion and the thermodynamics in the case of spherically symmetric solutions in $f(T)$ gravity using the perturbative approach. We consider small deviations from general relativity and we extract charged…
A class of viable $F(R)$ gravity models which can provide a unified description of inflation with the dark energy era is confronted with the latest observational data on the dark energy era. These models have the unique characteristic that…
In this paper, we investigate the topological number of de-Sitter black hole solutions with different charges $(q)$ and rotational $(a)$ parameters. By using generalized free energy and Duan's $\phi$-mapping topological current theory, we…
We construct regular black holes with anti-de Sitter asymptotics in theories incorporating infinite towers of higher-order curvature corrections in any dimension $D \ge 5$. We find that regular black branes are generically inner-extremal,…
We consider phenomenological models for nonsingular black holes that satisfy the limiting curvature condition (i.e., that have curvatures that are always sub-Planckian in size) while having a more general dependence on the black hole mass…
Inflation provides a suitable environment for the formation of Primordial Black Holes(PBHs). In this article, we examine the formation of primordial black holes in the Mutated Hilltop inflation model coupled with the Einstein-Gauss-Bonnet…
The $SL(2,R)/U(1)$ gauged WZWN model is modified by a topological term and the accompanying change in the geometry of the two dimensional target space is determined. The possibility of this additional term arises from a symmetry in the…
We investigate the inflation for the quartic hilltop model via a certain type of modified gravity. Precisely, we analyze the $F(\phi) T$ term in the Einstein's gravity to examine the quartic hilltop inflation model. $T$ is the trace of the…
Within the framework of hybrid metric-Palatini gravity, we incorporate non-localities introduced via the inverse of the d'Alembert operators acting on the scalar curvature. We analyse the dynamical structure of the theory and, adopting a…
We find that if general relativity is modified at the Planck scale by a Ricci-squared term, electrically charged black holes may be nonsingular. These objects concentrate their mass in a microscopic sphere of radius $r_{core}\approx…
The singularity of a spherical (Schwarzschild) black hole is a surface, not a point. A freely-falling, non-rotating observer sees Hawking radiation with energy density diverging with radius as $\rho \propto r^{-6}$ near the Schwarzschild…
We investigate the possibility that the Universe may inflate due to moduli fields, corresponding to flat directions of supersymmetry, lifted by supergravity corrections. Using a hybrid-type potential we obtain a two-stage inflationary…
Motivated by the fact that the pre-inflationary era may evolve in an exotic way, in this work we formalize anisotropic evolution in the context of modified gravity, focusing on pre-inflationary and near the vicinity of the inflationary…
Regular black holes represent a conservative model in which the classical singularity is replaced by a non-singular core without necessarily modifying the spacetime outside the trapping horizon. Given the possible lack of phenomenological…
Some well-known metrics used as models of static non-rotating black holes are considered. These are the Reissner-Nordstrom-de Sitter, Bardeen-Kiselev and McVittie models. A significant difference between them in how adequately they can…