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In this work, two originally separate adjustments for the Friedmann equations are concurrently considered. Firstly, the fractal structure of the black hole horizon region is imposed by the Barrow entropy. The second adjustment is the…

General Relativity and Quantum Cosmology · Physics 2024-06-13 Tuhina Ghorui , Prabir Rudra , Farook Rahaman

The universe media is considered as a non-perfect fluid with bulk viscosity and described by a more general equation of state. We assume the bulk viscosity is a linear combination of the two terms: one is constant, and the other is…

Astrophysics · Physics 2009-03-19 Xin-He Meng , Jie Ren , Ming-Guang Hu

The thermodynamics-gravity conjecture reveals that one can derive the gravitational field equations by using the first law of thermodynamics and vice versa. Considering the entropy associated with the horizon in the form of non-extensive…

General Relativity and Quantum Cosmology · Physics 2021-11-04 Mahnaz Asghari , Ahmad Sheykhi

Over the past decades, the role of torsion in gravity has been extensively investigated along the main direction of bringing gravity closer to its gauge formulation and incorporating spin in a geometric description. Here we review various…

General Relativity and Quantum Cosmology · Physics 2016-09-09 Yi-Fu Cai , Salvatore Capozziello , Mariafelicia De Laurentis , Emmanuel N. Saridakis

Recently, a generalized gravity theory was proposed by Harko etal where the Lagrangian density is an arbitrary function of the Ricci scalar R and the trace of the stress-energy tensor T, known as F(R,T) gravity. In their derivation of the…

General Physics · Physics 2015-06-12 Subenoy Chakraborty

We investigate models of future finite-time singularities in $f(T)$ theory, where $T$ is the torsion scalar. The algebraic function $f(T)$ is put as the teleparallel term $T$ plus an arbitrary function $g(T)$. A suitable expression of the…

General Relativity and Quantum Cosmology · Physics 2013-03-26 M. R. Setare , M. J. S. Houndjo

A model with flat FRW symmetries and G and Lambda variable,is considered in such a way that the momentum-energy tensor that describes the model is characterized by a bulk viscosity parameter. In this paper it is showed how to apply the…

General Physics · Physics 2007-05-23 J. A. Belinchon

In this paper, we consider the flat Friedmann Lematre Robertson-Walke metric in the presence of perfect fluid models and extended $f(R,G,T)$ gravity (where $R$ is the Ricci scalar, $G$ is the Gauss Bonnet invariant and $T$ stands for trace…

General Relativity and Quantum Cosmology · Physics 2022-12-21 M. Ilyas , Aftab Ahmad , Fawad Khan , M. Wasif

We derive a Tolman-Oppenheimer-Volkoff equation in neutron star systems within the modified $f(T, \mathcal{T})$-gravity class of models using a perturbative approach. In our approach $f(T, \mathcal{T})$-gravity is considered to be a static…

General Relativity and Quantum Cosmology · Physics 2017-05-08 Mark Pace , Jackson Levi Said

The universe content is considered as a non-perfect fluid with bulk viscosity and can be described by a general equation of state (endowed some deviation from the conventionally assumed cosmic perfect fluid model). An explicitly bulk…

Astrophysics · Physics 2009-10-16 X H Meng , X Dou

Dynamical analysis of spherically symmetric collapsing star surrounding in locally anisotropic environment with expansion-free condition is presented in $f(R,T)$ gravity, where $R$ corresponds to Ricci scalar and $T$ stands for the trace of…

General Relativity and Quantum Cosmology · Physics 2015-04-21 Ifra Noureen , M. Zubair

The present paper is elaborated to discuss the energy condition bounds in a modified teleparallel gravity namely $F(T,T_{G})$, involving torsion invariant $T$ and contribution from a term $T_G$, the teleparallel equivalent of the…

General Relativity and Quantum Cosmology · Physics 2015-09-23 Saira Waheed , M. Zubair

New high-precision observations are now possible to constrain different gravity theories. To examine the accelerated expansion of the Universe, we used the newly proposed $f(Q,T)$ gravity, where $Q$ is the non-metricity, and $T$ is the…

General Relativity and Quantum Cosmology · Physics 2021-06-30 Simran Arora , Abhishek Parida , P. K. Sahoo

We investigate a flat FLRW-model in $f(R,T)$-gravity, which includes the quadratic variation in scalar curvature $R$ and the linear term of the trace of the stress-energy tensor $T$. In turn, we establish the model has the behaviour of the…

General Relativity and Quantum Cosmology · Physics 2022-08-10 J. K. Singh , Akanksha Singh , G. K. Goswami , J. Jena

In recent few years, the Gauss-Bonnet $f(\mathcal{G},\mathrm{\textit{T}})$ theory of gravity has fascinated considerable researchers owing to its coupling of trace of the stress-energy tensor $T$ with the Gauss-Bonnet term $\mathcal{G}$. In…

General Relativity and Quantum Cosmology · Physics 2023-04-14 Mushtaq Ahmad , M. Farasat Shamir , G. Mustafa

We present a systematic analysis of the dynamics of flat Friedmann-Lema\^{i}tre-Robertson-Walker cosmological models with radiation and dust matter in generalized teleparallel $f(T)$ gravity. We show that the cosmological dynamics of this…

General Relativity and Quantum Cosmology · Physics 2017-09-05 Manuel Hohmann , Laur Jarv , Ulbossyn Ualikhanova

In this article we study the hydrostatic equilibrium configuration of neutron stars (NSs) and strange stars (SSs), whose fluid pressure is computed from the equations of state $p=\omega\rho^{5/3}$ and $p=0.28(\rho-4{\cal B})$, respectively,…

General Relativity and Quantum Cosmology · Physics 2018-08-17 P. H. R. S. Moraes , J. D. V. Arbañil , G. A. Carvalho , R. V. Lobato , E. Otoniel , R. M. Marinho , M. Malheiro

The present work is based on the idea of an interacting framework of new holographic dark energy with cold dark matter in the background of $f(T)$ gravity. Here, we have considered the flat modified Friedmann universe for $f(T)$ gravity…

General Relativity and Quantum Cosmology · Physics 2016-02-17 Chayan Ranjit , Prabir Rudra

In this paper, we construct an isotropic cosmological model in the $ f(Q, T) $ theory of gravity in the frame of a flat FLRW spacetime being $ Q $ the non-metricity tensor and $ T $ the trace of the energy-momentum tensor. The gravity…

General Relativity and Quantum Cosmology · Physics 2025-04-24 Akanksha Singh , Shaily , J. K. Singh , Ertan Güdekli

The whole article deals with the analysis of the cosmic model of Ruban's space-time in the context of a bulk viscosity impact in the form of Ricci dark energy within the framework Brans-Dicke theory (Brans and Dicke, Phys. Rev. 124, 925…

General Relativity and Quantum Cosmology · Physics 2023-11-03 M. Vijayasanthi , T. Chinnappalanaidu , S. Srivani Madhu