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Related papers: Cosmic scenarios in $f(R)$ gravity: a complete evo…

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The homogeneous and isotropic cosmological model in generalized $ f(R,T^\phi) $ theories associated with scalar field is discussed, which is motivated by the $ f(R,T) $ theory of gravity studied by Harko et al. \cite{Harko:2011kv,…

General Relativity and Quantum Cosmology · Physics 2022-12-27 J. K. Singh , Akanksha Singh , Shaily , J. Jena

For higher-derivative f(R) gravity where R is the Ricci scalar, a class of models is proposed which produce viable cosmology different from the LambdaCDM one at recent times and satisfy cosmological, Solar system and laboratory tests. These…

Astrophysics · Physics 2009-07-09 Alexei A. Starobinsky

Present investigation devoted to the dynamical study of Relativistic Hydrodynamics with some thermodynamical characteristics in $f(R,G)$ gravity towards spatially homogeneous isotropic cosmological model filled with isotropic fluid. We…

General Physics · Physics 2020-04-09 S. H. Shekh , Simran Arora , V. R. Chirde , P. K. Sahoo

Standard dynamical system analysis of Einstein-Maxwell equation in $f(R)$ theories is considered in this work. We investigate cosmological dynamics of a uniform magnetic field in the Orthogonal Spatially Homogeneous (OSH) Bianchi type I…

General Relativity and Quantum Cosmology · Physics 2018-01-09 Xuyang Liu , Phongpichit Channuie , Daris Samart

A perfect fluid, spatially flat cosmology in a $f(T)$ model, derived from a recently proposed general Born-Infeld type theory of gravity is studied. Four dimensional cosmological solutions are obtained assuming the equation of state…

General Relativity and Quantum Cosmology · Physics 2014-12-04 Soumya Jana

The cosmological implications of an evolutionary quantum gravity are analyzed in the context of a generic inhomogeneous model. The Schr\"{o}dinger problem is formulated and solved in the presence of a scalar field, an ultrarelativistic…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Marco Valerio Battisti , Giovanni Montani

The present study is motivated by the study of reference [1], where the generalized second law of thermodynamics has been investigated for a flat FRW universe for two viable models of $f(T)$ gravity. In the present work, we have considered…

General Relativity and Quantum Cosmology · Physics 2013-11-22 Rahul Ghosh , Antonio Pasqua , Surajit Chattopadhyay

We study the future evolution of quintessence/phantom dominated epoch in modified $F(R)$-gravity which unifies the early-time inflation with late-time acceleration and which is consistent with observational tests. Using the reconstruction…

High Energy Physics - Theory · Physics 2008-11-26 Shin'ichi Nojiri , Sergei D. Odintsov

The $f(Q,C)$ theory, which extends symmetric teleparallel gravity by including the boundary term $C$ in addition to the non-metricity scalar $Q$, provides a unifying framework that encompasses both $f(Q)$ and $f(\mathring{R})$ gravities. In…

General Relativity and Quantum Cosmology · Physics 2025-09-30 Hamid Shabani , Avik De

In this work we consider the realization of a variant emergent Universe scenario in the context of $f(R)$ gravity. We use well-known reconstruction techniques existing in the literature, and we find the approximate form of the vacuum $f(R)$…

General Relativity and Quantum Cosmology · Physics 2024-03-18 V. K. Oikonomou , Gregory K. Kafanelis

While the use of numerical general relativity for modeling astrophysical phenomena and compact objects is commonplace, the application to cosmological scenarios is only just beginning. Here, we examine the expansion of a spacetime using the…

General Relativity and Quantum Cosmology · Physics 2016-06-27 John T. Giblin , James B. Mertens , Glenn D. Starkman

We investigate inflation within $f(R,\phi)$-theories, where a dynamical scalar field is coupled to gravity. A class of models which can support early-time acceleration with the emerging of an effective cosmological constant at high…

General Relativity and Quantum Cosmology · Physics 2018-12-13 R. Myrzakulov , L. Sebastiani , S. Vagnozzi

We propose a new formulation of $f(R)$ gravity, dubbed scalarized $f(R)$ gravity, in which the Legendre transform is included as a dynamical term. This leads to a theory with second-order field equations that describes general relativity…

General Relativity and Quantum Cosmology · Physics 2023-06-07 Spiros Cotsakis , Jose P. Mimoso , John Miritzis

We survey the landscape of $f(R)$ theories of gravity in their various formulations, which have been used to model the cosmic acceleration as alternatives to dark energy and dark matter. Besides, we take into account the problem of…

General Relativity and Quantum Cosmology · Physics 2015-05-14 S. Capozziello , M. De Laurentis , V. Faraoni

In this work, we consider F(R) alternative theories of gravity with an eye to Noether symmetry through the gauge theorem. For non-vacuum models, one finds {\Lambda} like gravity with energy density of Chaplygin Gas. We also obtain the…

General Relativity and Quantum Cosmology · Physics 2018-06-19 H. R. Fazlollahi

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

Modified gravity is one of the most promising candidates for explaining the current accelerating expansion of the Universe, and even its unification with the inflationary epoch. Nevertheless, the wide range of models capable to explain the…

General Relativity and Quantum Cosmology · Physics 2015-06-03 Álvaro de la Cruz-Dombriz , Diego Sáez-Gómez

Intrigued by the holographic principle, Padmanabhan recently proposed a novel idea, saying that our cosmic space is emergent as cosmic time progresses. In particular, the expansion rate of the Universe is related to the difference between…

High Energy Physics - Theory · Physics 2013-09-12 Yi Ling , Wen-Jian Pan

We study the late time cosmological evolution of $f(R)$ theories of modified gravity, with the matter content of the universe being that of collisional self interacting matter. We assume that the universe is described by a flat…

General Relativity and Quantum Cosmology · Physics 2015-06-22 V. K. Oikonomou , N. Karagiannakis

We use a dynamical system approach to study the cosmological viability of $f(R,\mathcal{G})$ gravity theories. The method consists of formulating the evolution equations as an autonomous system of ODEs, using suitable variables. The…

General Relativity and Quantum Cosmology · Physics 2018-03-12 Simony Santos da Costa , Fernando V. Roig , Jailson S. Alcaniz , Salvatore Capozziello , Mariafelicia de Laurentis , Micol Benetti