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In today's scenario, going beyond Einstein's theory of gravity leads us to some more complete and modified gravity theories. One of them is the $f(R,T)$ gravity in which $ R $ is the Ricci scalar, and $ T $ is the trace of the…

General Relativity and Quantum Cosmology · Physics 2022-01-04 P. K. Sahoo , Sanjay Mandal , Simran Arora

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

We investigate the cosmological applications of a bi-scalar modified gravity that exhibits partial conformal invariance, which could become full conformal invariance in the absence of the usual Einstein-Hilbert term and introducing…

General Relativity and Quantum Cosmology · Physics 2016-04-27 Emmanuel N. Saridakis , Minas Tsoukalas

The usual Einstein's equations is modified as a one parameter family of equations in the framework of rainbow gravity. In this paper we derive the modified Friedmann-Robertson-Walker (FRW) equations when the cosmological evolution of…

General Relativity and Quantum Cosmology · Physics 2010-04-15 Yi Ling , Qingzhang Wu

In the context of a ghost free $f(R,\mathcal{G})$ model, an extended matter bounce scenario is studied where the form of the scale factor is given by $a(t) = (a_0t^2 + 1)^n$. The ghost free character of the model is ensured by the presence…

General Relativity and Quantum Cosmology · Physics 2020-04-22 E. Elizalde , S. D. Odintsov , V. K. Oikonomou , Tanmoy Paul

In this paper, we investigate the stability of the flat FLRW metric in $f(T)$ gravity. This is achieved by analysing the small perturbations, $\delta$ about the Hubble parameter and the matter energy density, $\delta_\text{m}$. We find that…

General Relativity and Quantum Cosmology · Physics 2017-01-03 Gabriel Farrugia , Jackson Levi Said

We study the energy conditions in the framework of the modi- fied gravity with higher-derivative torsional terms in the action. We discuss the viability of the model by studying the energy conditions in terms of the cosmographical…

General Relativity and Quantum Cosmology · Physics 2017-06-07 Tahereh Azizi , Miysam Gorjizadeh

We study cosmological evolution in a flat FLRW spacetime in the context of modified STEGR gravity or $f(Q)$, using an exponential two-parameter model which represents a smooth perturbative expansion around the $\Lambda$CDM model. The…

General Relativity and Quantum Cosmology · Physics 2025-04-15 Ivan R. Vasquez , A. Oliveros

We consider a class of metric f(R) modified gravity theories, analyze them in the context of a Friedmann-Robertson-Walker cosmology and confront the results with some of the known constraints imposed by observations. In particular, we focus…

General Relativity and Quantum Cosmology · Physics 2012-06-11 Luisa G. Jaime , Leonardo Patino , Marcelo Salgado

The propagation of gravitational waves or tensor perturbations in a perturbed Friedmann-Robertson-Walker universe filled with a perfect fluid is re-examined. It is shown that while the shear and magnetic part of the Weyl tensor satisfy…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Peter Dunsby , Bruce Bassett , George Ellis

In this paper we obtain some cosmological solutions that describe the present period of accelerating expansion of the universe in the framework of a geometrical gauge scalar-tensor theory of gravity. The background geometry in the model is…

General Relativity and Quantum Cosmology · Physics 2023-03-08 José Edgar Madriz Aguilar , M. Montes , A. Bernal

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

In this paper, we discuss cosmological application of holographic Dark Energy (HDE) in the framework of $f(G)$ modified gravity. For this purpose, we construct $f(G)$ model with the inclusion of HDE and a well-known power law form of the…

General Physics · Physics 2015-06-12 Abdul Jawad , Antonio Pasqua , Surajit Chattopadhyay

We investigate a spatially flat FLRW cosmological model in the framework of modified gravity described by the function \( f(R, L_m) = \alpha R + L_m^\beta + \gamma \), where \( L_m \) is the matter Lagrangian density. The modified Friedmann…

General Relativity and Quantum Cosmology · Physics 2026-02-05 G. K. Goswami , Anirudh Pradhan , Syamala Krishnannair

In the context of the late time cosmic acceleration phenomenon, many geometrically modified theories of gravity have been proposed in recent times. In this paper, we have investigated the role of a recently proposed extension of symmetric…

General Relativity and Quantum Cosmology · Physics 2021-08-16 A. S. Agrawal , Laxmipriya Pati , S. K. Tripathy , B. Mishra

Using a correspondence between the f(T)-gravity with the power-law entropy corrected version of the holographic dark energy model, we reconstruct the holographic f(T)-gravity model with power-law entropy correction. We fit the model…

General Relativity and Quantum Cosmology · Physics 2013-11-06 K. Karami , S. Asadzadeh , A. Abdolmaleki , Z. Safari

We attempt to construct a Friedmann-Lemaitre-Robertson-Walker(FLRW) cosmological model in $f(R, T)$ gravity which exhibits a phase transition from deceleration to acceleration at present. We take $f(R,T) = R + 2 \lambda T$, $\lambda$ being…

General Relativity and Quantum Cosmology · Physics 2023-06-05 Anirudh Pradhan , Gopikant Goswami , Rita Rani , Aroonkumar Beesham

The usual interpretation of Weyl geometry is modified in two senses. First, both the additive Weyl connection and its variation are treated as (1, 2) tensors under the action of Weyl covariant derivative. Second, a modified covariant…

General Relativity and Quantum Cosmology · Physics 2013-09-18 Fang-Fang Yuan , Yong-Chang Huang

In this paper we use the conformal teleparallel gravity to study an isotropic and homogeneous Universe which is settled by the FRW metric. We solve the field equations and we obtain the behavior of some cosmological parameters such as scale…

General Relativity and Quantum Cosmology · Physics 2016-03-30 J. G. Silva , A. F. Santos , S. C. Ulhoa

The dynamics of perfect fluid as a source in the context of modified gravity, specifically $f(Q,T)$ gravity, are examined within the Friedmann-Lema\^itre-Robertson-Walker (FLRW) cosmological model. This gravity is a generic function of the…

General Relativity and Quantum Cosmology · Physics 2024-08-02 S. H. Shekh , Anirudh Pradhan , S. P. Gaikwad , K. R. Mule