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Related papers: Cosmological solutions in teleparallel $F(T,B)$ gr…

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In a recent article, Faraoni proposed an alternative procedure to solve the Friedman-Lemaitre-Robertson-Walker (FLRW) cosmological equations. The basic result of that paper was obtained long ago through a different approach, which seems to…

Astrophysics · Physics 2015-06-24 J. A. S. Lima

We study Friedmann-Robertson-Walker cosmological models with matter content composed of two perfect fluids $\rho_1$ and $\rho_2$, with barotropic pressure densities $p_1/ \rho_1=\omega_1=const$ and $p_2/ \rho_2=\omega_2=const$, where one of…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Mauricio Cataldo , Fabiola Arevalo , Paul Minning

This paper studies the viable regions of some cosmic models in a higher derivative $f(R,\square R, T)$ theory with the help of energy conditions (where $R$ and $T$ are the Ricci scalar, and trace of energy momentum tensor, respectively).…

General Relativity and Quantum Cosmology · Physics 2020-03-03 M. Ilyas , Z. Yousaf , M. Z. Bhatti

Cosmological perturbations in Loop Quantum Cosmology (LQC) are usually studied incorporating either holonomy corrections, where the Ashtekar connection is replaced by a suitable sinus function in order to have a well-defined quantum…

General Relativity and Quantum Cosmology · Physics 2015-06-17 Jaime Haro

We report a new symmetry of the Einstein-Friedmann equations for spatially flat Friedmann- Lema\^itre-Robertson-Walker universes. We discuss its application to barotropic perfect fluids and its use as a solution-generating technique for…

General Relativity and Quantum Cosmology · Physics 2020-12-02 Steve Dussault , Valerio Faraoni

Present work deals with the two fluid Bianchi Type-V cosmological models consisting of matter and radiating source in the $f(R, T)$ theory of gravity studied by Harko et al. (2011). In this paper, we developed a new idea about $f(R, T)$…

General Relativity and Quantum Cosmology · Physics 2023-03-24 Y. S. Solanke , Sandhya Mhaske , D. D. Pawar , V. J. Dagwal

The torsion models have stood out among the proposals for an alternative description of gravity. The simplest of them, the Teleparallel theory, is equivalent to General Relativity and there are many studies that seek to study its extension…

General Relativity and Quantum Cosmology · Physics 2022-12-09 H. G. M. Fortes , J. C. N. de Araujo

In this paper, a general FRW cosmological model has been constructed in $f(R,T)$ gravity reconstruction with variable cosmological constant. A number of solutions to the field equations has been generated by utilizing a form for the Hubble…

General Relativity and Quantum Cosmology · Physics 2018-10-17 Nasr Ahmed , Sultan Z. Alamri

We consider spatially homogeneous and isotropic Friedmann-Robertson-Walker (FRW) solutions of Milgrom's recently proposed class of bimetric theories of gravity. These theories have two different regimes, corresponding to high and low…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Timothy Clifton , Thomas G. Zlosnik

We study the classical and quantum models of a Friedmann-Robertson-Walker (FRW) cosmology, coupled to a perfect fluid, in the context of the scalar-metric gravity. Using the Schutz' representation for the perfect fluid, we show that, under…

General Relativity and Quantum Cosmology · Physics 2014-11-20 Babak Vakili

This manuscript is devoted to investigate Bianchi Type $I$ universe in the context of $f(R,T)$ gravity. For this purpose, we explore the exact solutions of locally rotationally symmetric Bianchi type $I$ spacetime. The modified field…

General Physics · Physics 2015-08-07 M. Farasat Shamir

In this paper, we intend to evaluate and analyze the statefinder parameters in $f(T)$ cosmology. Friedmann equation in $f(T)$ model is taken, and the statefinder parameters ${r,s}$ are calculated. We consider a model of $f(T)$ which…

General Physics · Physics 2012-11-13 Mubasher Jamil , Davood Momeni , Ratbay Myrzakulov , Prabir Rudra

We study modified $f(R,(\nabla R)^2,\square R)$ gravity and show in detail how it can be reduced to Einstein gravity with a few scalar fields and then represented in the form of chiral self-gravitating model of the special type. In further…

General Relativity and Quantum Cosmology · Physics 2024-10-10 Tatyana Chaadaeva , Sergey Chervon

In this paper, we present the cosmological scenario obtained from $f(R,T)$ gravity by using an exponential dependence on the trace of the energy-momentum tensor. With a numerical approach applied to the equations of motion, we show several…

General Relativity and Quantum Cosmology · Physics 2019-11-11 G. Ribeiro , R. Sfair , P. H. R. S. Moraes , J. R. L. Santos , A. de Souza Dutra

Several extensions of General Relativity and high energy physics include scalar fields as extra degrees of freedom. In the search for predictions in the non-linear regime of cosmological evolution, the community makes use of numerical…

Cosmology and Nongalactic Astrophysics · Physics 2014-09-04 Claudio Llinares , David Mota

We show that there are no new consistent cosmological perfect fluid solutions when in an open neighbourhood ${\cal U}$ of an event the fluid kinematical variables and the electric and magnetic Weyl curvature are all assumed rotationally…

General Relativity and Quantum Cosmology · Physics 2014-11-17 Nazeem Mustapha , George F R Ellis , Henk van Elst , Mattias Marklund

The field equations of a special class of teleparallel theory of gravitation and electromagnetic fields have been applied to tetrad space having cylindrical symmetry with four unknown functions of radial coordinate $r$ and azimuth angle…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Gamal G. L. Nashed

The field equations derived from the low energy string effective action with a matter tensor describing a perfect fluid with a barotropic equation of state are solved iteratively using the long-wavelength approximation, i.e. the field…

General Relativity and Quantum Cosmology · Physics 2015-06-25 Piret Kuusk , Margus Saal

We investigate the geometrodynamical effects of introducing the boundary term in symmetric teleparallel gravity. Specifically, we consider a homogeneous and isotropic universe in $f\left( Q, B \right) $, where $Q$ is the non-metricity…

General Relativity and Quantum Cosmology · Physics 2023-09-27 Andronikos Paliathanasis

This paper is devoted to investigate the exact solutions of Bianchi types I and V spacetimes in the context of f(R, T) gravity [1]. For this purpose, we found two exact solutions in each case by using assumption of constant deceleration…

General Relativity and Quantum Cosmology · Physics 2012-07-04 M. Farasat Shamir , Adil Jhangeer , Akhlaq Ahmad Bhatti
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