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Related papers: Viscous cosmology in $f(T)$ gravity

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We consider the cosmological evolution of a flat anisotropic Universe in $f(T)$ gravity in the presence of a perfect fluid. It is shown that the matter content of the Universe has a significant impact of the nature of a cosmological…

General Relativity and Quantum Cosmology · Physics 2021-06-10 Maria A. Skugoreva , Alexey V. Toporensky

Decaying dark matter models generically modify the equation of state around the time of dark matter decay, and this in turn modifies the expansion rate of the Universe through the Friedmann equation. Thus, a priori, these models could solve…

Cosmology and Nongalactic Astrophysics · Physics 2023-07-04 Andreas Nygaard , Emil Brinch Holm , Thomas Tram , Steen Hannestad

In this paper we are to study homogeneous and anisotropic Bianchi type-V universe in presence of bulk viscous fluid source of matter with time function gravitational constant G and cosmological term lambda. The viscosity coefficient is…

General Relativity and Quantum Cosmology · Physics 2023-05-19 Nawsad Ali

In this article, we attempt to describe cosmic late-time acceleration of the universe in the framework of $f(R,L_m)$ gravity by using an effective equation of state when the account is taken of bulk viscosity. We presume a non-linear…

General Relativity and Quantum Cosmology · Physics 2023-03-31 Lakhan V. Jaybhaye , Raja Solanki , Sanjay Mandal , Pradyumn Kumar Sahoo

We consider the evolution of a flat, isotropic and homogeneous Friedmann-Robertson-Walker Universe, filled with a causal bulk viscous cosmological fluid, that can be characterized by an ultra-relativistic equation of state and bulk…

General Relativity and Quantum Cosmology · Physics 2011-10-05 A. Tawfik , M. Wahba , H. Mansour , T. Harko

In this paper, we study the $f(T,\mathcal{T})$ gravity model in the presence of the bulk viscosity by the flat-FRW metric. The field equation is obtained by teleparallel gravity with tetrad field. The universe components are considered as…

General Relativity and Quantum Cosmology · Physics 2020-12-18 T. Mirzaei-Rezaei , Alireza Amani , E. Yusofi , S. Rouhani , M. A. Ramzanpour

We use dynamical system methods to explore the general behaviour of $f(T)$ cosmology. In contrast to the standard applications of dynamical analysis, we present a way to transform the equations into a one-dimensional autonomous system,…

General Relativity and Quantum Cosmology · Physics 2018-03-14 A. Awad , W. El Hanafy , G. G. L. Nashed , Emmanuel N. Saridakis

The viscosity of dark matter in cosmological models may cause an accelerated expansion and when this effect is sufficiently large, it can explain the dark energy. In this work, attributing the origin of viscosity to self-interaction of dark…

Cosmology and Nongalactic Astrophysics · Physics 2019-02-27 Abhishek Atreya , Jitesh R. Bhatt , Arvind Kumar Mishra

We consider the evolution of a flat Friedmann-Robertson-Walker Universe, filled with a causal bulk viscous cosmological fluid, in the presence of variable gravitational and cosmological constants. The basic equation for the Hubble…

General Relativity and Quantum Cosmology · Physics 2008-11-26 M. K. Mak , J. A. Belinchon , T. Harko

We consider the influence of the perturbative bulk viscosity on the evolution of the Hubble parameter in the QCD era of the early Universe. For the geometry of the Universe we assume the homogeneous and isotropic…

General Relativity and Quantum Cosmology · Physics 2010-11-24 A. Tawfik , M. Wahba , H. Mansour , T. Harko

In this work we present a further investigation about Teleparallel Gravity Cosmology. We demonstrate that according the current astrophysical data (CC+Pantheon+BAO samplers with late universe measurements SH0ES+H0LiCOW), an $f(T,B)$ theory…

General Relativity and Quantum Cosmology · Physics 2021-05-07 Celia Escamilla-Rivera , Jackson Levi Said

We explore the viability of a bulk viscous matter-dominated Universe to explain the present accelerated expansion of the Universe. The model is composed by a pressureless fluid with bulk viscosity of the form \zeta = \zeta_0 + \zeta_1 * H…

General Relativity and Quantum Cosmology · Physics 2010-10-25 Arturo Avelino , Ulises Nucamendi

We investigated a bulk viscous fluid universe with cosmological constant {\Lambda} by assuming that the bulk viscosity to be proportional to the Hubble parameter. We found that for an expanding universe, the (relative) matter density will…

General Relativity and Quantum Cosmology · Physics 2024-01-25 Jinwen Hu , Huan Hu

In this paper, the dynamical behavior of the anisotropic universe has been investigated in $f(R,T)$ theory of gravity. The functional $f(R,T)$ has been rescaled in the form $f(R,T)=\mu R+\mu T$, where $R$ is the Ricci scalar and $T$ is the…

General Physics · Physics 2018-01-08 B. Mishra , S Tarai , S. K. J. Pacif

This study proposes a unified framework comprising two complementary approaches to constrain three functional forms of $f(T,B)$ gravity, namely the linear, quadratic, and general power law models, by jointly utilizing early and late…

Cosmology and Nongalactic Astrophysics · Physics 2026-01-07 Yahia Al-Omar , Majida Nahili , Nidal Chamoun , Marwan Al-Raeei

We investigate the out-of-equilibrium dynamics of viscous fluids in a spatially flat Friedmann-Lema\^itre-Robertson-Walker cosmology using the most general causal and stable viscous energy-momentum tensor defined at first order in spacetime…

General Relativity and Quantum Cosmology · Physics 2023-07-31 Fábio S. Bemfica , Marcelo M. Disconzi , Jorge Noronha , Robert J. Scherrer

The research on relativistic universe models with viscous fluids is reviewed. Viscosity may have been of significance during the early inflationary era, and may also be of importance for the late time evolution of the Universe. Bulk…

General Relativity and Quantum Cosmology · Physics 2014-10-01 Iver Brevik , Øyvind Grøn

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

We present the coupling of the torsion scalar $T$ and the trace of energy-momentum tensor $\mathcal{T}$, which produces new modified $f(T,\mathcal{T})$ gravity. Moreover, we consider the functional form $f(T,\mathcal{T}) =\alpha…

General Relativity and Quantum Cosmology · Physics 2023-03-13 Simran Arora , Aaqid Bhat , P. K. Sahoo

The concept of negative temperatures has occasionally been used in connection with quantum systems. A recent example of this sort is reported in the paper of S. Braun et al. [Science 339,52 (2013)], where an attractively interacting…

General Relativity and Quantum Cosmology · Physics 2013-10-01 Iver Brevik , Øyvind Grøn
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