arXiv subjects

M. Tavayef

Publications and source records attributed to M. Tavayef.

3 recordsLinked to original sources

arXiv2019

Black hole thermodynamics in the Sharma-Mittal generalized entropy formalism

Using the Sharma-Mittal entropy, we study some properties of the Schwarzschild and Schwarzschild-de Sitter black holes. The results are compared with those obtained by attributing the Bekenstein entropy bound to the mentioned black holes. Our main results show that while the Schwarzschild black hole is always stable in the micro-canonical ensemble, it can be stable in the canonical ensemble if its mass is bigger than the mass of the coldest Schwarzschild black hole. A semi-classical analysis has also been used to find an approximate relation between the entropy free parameters. Throughout the paper, we use units $c=G=\hbar=k_B=1$, where $k_B$ denotes the Boltzmann constant.

physics.gen-ph↗

arXiv2018

Tsallis Holographic Dark Energy

Employing the modified entropy-area relation suggested by Tsallis and Cirto \cite{non3}, and the holographic hypothesis, a new holographic dark energy (HDE) model is proposed. Considering a flat Friedmann-Robertson-Walker (FRW) universe in which there is no interaction between the cosmos sectors, the cosmic implications of the proposed HDE are investigated. Interestingly enough, we find that the identification of IR-cutoff with the Hubble radius, can lead to the late time accelerated Universe even in the absence of interaction between two dark sectors of the Universe. This is in contrast to the standard HDE model with Hubble cutoff, which does not imply the accelerated expansion, unless the interaction is taken into account.

gr-qc↗

arXiv2017

Revisiting Holographic Dark Energy in Cyclic Cosmology

Considering the holographic dark energy (HDE) with two different Infrared (IR) cutoffs, we study the evolution of a cyclic universe which avoids the Big-Rip singularity. Our results show that, even in the absence of a mutual interaction between the cosmos sectors, the HDE model with the Hubble radius as IR cutoff can mimics a cosmological constant in the framework of a cyclic cosmology. In addition, we find that both the interacting and non-interacting universes may enter into a cycle of sequential contraction and expansion, if the Granda-Oliveros (GO) cutoff is chosen as the IR cutoff in the energy density of the HDE.

gr-qc↗