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Related papers: Viable f(R) gravity and future cosmological evolut…

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We review recent developments on cosmology in extended teleparallel gravity, called "$F(T)$ gravity" with $T$ the torsion scalar in teleparallelism. We explore various cosmological aspects of $F(T)$ gravity including the evolution of the…

General Relativity and Quantum Cosmology · Physics 2015-05-05 Kazuharu Bamba

In this paper we demonstrate that with vacuum $F(G)$ gravity it is possible to describe the unification of late and early-time acceleration eras with the radiation and matter domination era. The Hubble rate of the unified evolution contains…

General Relativity and Quantum Cosmology · Physics 2016-06-22 V. K. Oikonomou

In this article we present the cosmological equivalence between the relativistic Finsler-Randers cosmology, with dark energy and modified gravity constructions, at the background level. Starting from a small deviation from the quadraticity…

General Relativity and Quantum Cosmology · Physics 2013-12-17 Spyros Basilakos , Alexandros P. Kouretsis , Emmanuel N. Saridakis , Panayiotis Stavrinos

In this work we consider a cosmological scenario in which the Universe contracts initially having a bouncing-like behavior, and accordingly after it bounces off, it decelerates following a matter dominated like evolution and at very large…

General Relativity and Quantum Cosmology · Physics 2020-12-02 S. D. Odintsov , V. K. Oikonomou , Tanmoy Paul

We investigate a simple generalization of the metric exponential $f(R)$ gravity theory that is cosmologically viable and compatible with solar system tests of gravity. We show that, as compared to other viable $f(R)$ theories, its steep…

Cosmology and Nongalactic Astrophysics · Physics 2013-11-26 M. O'Dwyer , S. E. Joras , I. Waga

Recently, corrections of the $L(R)$ type to Einstein-Hilbert action that become important at small curvature are proposed. Those type of models intend to explain the observed cosmic acceleration without dark energy. We derive the full…

Astrophysics · Physics 2009-11-10 Xinhe Meng , Peng Wang

Dark energy cosmology is considered in a modified Gauss-Bonnet model of gravity with and without a scalar field. It is shown that these generalizations of General Relativity endow it with a very rich cosmological structure: it may naturally…

General Relativity and Quantum Cosmology · Physics 2015-05-18 Emilio Elizalde , Ratbay Myrzakulov , Valery V. Obukhov , Diego Sáez-Gómez

This paper is devoted to explore modified $f(\mathcal{R})$ theories of gravity using Noether symmetry approach. For this purpose, Friedmann-Robertson-Walker spacetime is chosen to investigate the cosmic evolution. The study is mainly…

General Relativity and Quantum Cosmology · Physics 2020-02-21 M. Farasat Shamir

We review recent progress in the construction of modified gravity models as alternatives to dark energy as well as the development of cosmological tests of gravity. Einstein's theory of General Relativity (GR) has been tested accurately…

Cosmology and Nongalactic Astrophysics · Physics 2016-03-24 Kazuya Koyama

We propose a novel modified gravity: unimodular generalization of the Born-Infeld-$f(R)$ gravity within the framework of cosmology. After formulating the action corresponding to the generalized Born-Infeld-$f(R)$ gravity, we present a…

General Relativity and Quantum Cosmology · Physics 2024-02-16 Salih Kibaroğlu , Sergei D. Odintsov , Tanmoy Paul

This review explores modified theories of gravity, particularly $f(R)$ gravity, as extensions to General Relativity (GR) that offer alternatives to dark energy for explaining cosmic acceleration. These models generalize the Einstein-Hilbert…

General Relativity and Quantum Cosmology · Physics 2025-03-05 Rafid H. Dejrah

We discuss a modified form of gravity implying that the action contains a power \alpha of the scalar curvature. Coupling with the cosmic fluid is assumed. As equation of state for the fluid, we take the simplest version where the pressure…

General Relativity and Quantum Cosmology · Physics 2009-11-11 I. Brevik , O. Gorbunova , Y. A. Shaido

We consider the dynamics of tensor and scalar gravitational fields in the Relativistic Theory of Gravitation with the Minkowskian vacuum metric and generalize the formulation to the massless graviton. The potential of scalar field is…

High Energy Physics - Phenomenology · Physics 2007-05-23 V. V. Kiselev

We derive conditions under which f(G) gravity models, whose Lagrangian densities f are written in terms of a Gauss-Bonnet term G, are cosmologically viable. The most crucial condition to be satisfied is that f_GG, the second derivative of f…

High Energy Physics - Theory · Physics 2009-04-18 Antonio De Felice , Shinji Tsujikawa

A general formalism to investigate Bianchi type $VI_h$ universes is developed in an extended theory of gravity. A minimally coupled geometry and matter field is considered with a rescaled function of $f(R,T)$ substituted in place of the…

General Physics · Physics 2018-03-28 B. Mishra , S. K. Tripathy , Sankarsan Tarai

Anisotropic cosmological models are constructed in $f(R,T)$ gravity theory to investigate the dynamics of universe concerning the late time cosmic acceleration. Using a more general and simple approach, the effect of the coupling constant…

General Physics · Physics 2018-10-05 B. Mishra , Sankarsan Tarai , S. K. Tripathy

We investigate the cosmological reconstruction in modified f(R,T) gravity, where R is the Ricci scalar and T the trace of the stress-energy tensor. Special attention is attached to the case in which the function f is given by f (R, T) = f1…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 M. J. S. Houndjo

We consider some cosmological aspects of nonlocal modified gravity with $\Lambda$ term, where nonlocality is of the type $R \mathcal{F}(\Box) R$. Using ansatz of the form $\Box R = r R +s,$ we find a few a(t) nonsingular bounce cosmological…

General Relativity and Quantum Cosmology · Physics 2015-08-20 I. Dimitrijevic , B. Dragovich , J. Grujic , Z. Rakic

Birkhoff's theorem is discussed in the frame of f(R) gravity by using its scalar-tensor representation. Modified gravity has become very popular at recent times as it is able to reproduce the unification of inflation and late-time…

General Relativity and Quantum Cosmology · Physics 2015-05-28 Salvatore Capozziello , Diego Sáez-Gómez

We investigate cosmological solutions of f(R,T) modified theories of gravity for perfect fluid in spatially FLRW metric through phase space analysis, where R is Ricci scalar and T denotes the trace of energy-momentum tensor of matter…

General Relativity and Quantum Cosmology · Physics 2017-05-23 Hamid Shabani , Mehrdad Farhoudi
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