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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

In modified gravity theories that seek to explain cosmic acceleration, dwarf galaxies in low density environments can be subject to enhanced forces. The class of scalar-tensor theories, which includes f(R) gravity, predict such a force…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Bhuvnesh Jain , Jake Vanderplas

In this work we investigate the asymptotic cosmological dynamics of a modified gravity model based on the $f(R,T^\phi)$ theory, where $R$ denotes the Ricci scalar and $T^\phi$ is the trace of the stress-energy tensor of a scalar field.…

General Relativity and Quantum Cosmology · Physics 2025-12-25 Joaquin Estevez-Delgado , Roberto De Arcia , Gabino Estevez-Delgado , Israel Quiros

In this article we study the hydrostatic equilibrium configuration of neutron stars (NSs) and strange stars (SSs), whose fluid pressure is computed from the equations of state $p=\omega\rho^{5/3}$ and $p=0.28(\rho-4{\cal B})$, respectively,…

General Relativity and Quantum Cosmology · Physics 2018-08-17 P. H. R. S. Moraes , J. D. V. Arbañil , G. A. Carvalho , R. V. Lobato , E. Otoniel , R. M. Marinho , M. Malheiro

In this paper, we study the slowly rotating neutron stars in $f(R, T)$ gravity based on Hartle-Thorne formalism. We first consider the simplest matter-geometry coupled modified gravity, namely $f(R, T)=R+2\chi T$. We compute the mass,…

General Relativity and Quantum Cosmology · Physics 2024-09-16 Masum Murshid , Mehedi Kalam

For the accurate understanding of compact objects such as neutron stars and strange stars, the Tolmann-Openheimer-Volkof (TOV) equation has proved to be of great use. Hence, in this work, we obtain the TOV equation for the…

General Relativity and Quantum Cosmology · Physics 2019-11-07 G. A. Carvalho , S. I. dos Santos, , P. H. R. S. Moraes , M. Malheiro

We review the status of $f(R,T)$ cosmological models, where $T$ is the trace of the energy momentum tensor $T^{\mu\nu}$. We start focusing on the modified Friedmann equations for the minimally coupled gravitational Lagrangian of the type…

Cosmology and Nongalactic Astrophysics · Physics 2024-03-08 Ana Paula Jeakel , Jonas Pinheiro da Silva , Hermano Velten

The unknown physical nature of the Dark Energy motivates in cosmology the study of modifications of the gravity theory at large distances. One of these types of modifications is to consider gravity theories, generally termed as $f(R)$. In…

Cosmology and Nongalactic Astrophysics · Physics 2022-06-07 Pedro Bessa , Marcela Campista , Armando Bernui

In this paper, we have studied $F(R,T)$ gravity as an arbitrary function of curvature and torsion scalars in Friedmann--Lema\^{\i}tre--Robertson--Walker (FLRW) background. Then, we have considered interacting model between $F(R,T)$ gravity…

General Relativity and Quantum Cosmology · Physics 2023-07-19 Ali R. Amani , S. L. Dehneshin

Evolved stars dominate galactic spectra, enrich the galactic medium, expand to change their planetary systems, eject winds of a complex nature, produce spectacular nebulae and illuminate them, and transfer material between binary…

This study presents new spherically symmetric and dynamical wormhole solutions supported by ordinary matter modeled as an anisotropic fluid, exhibiting a traversable nature. To achieve this goal, we adopt different approaches to obtain both…

General Relativity and Quantum Cosmology · Physics 2025-04-29 M. Zubair , Hina Azmat , Quratulien Muneer , Saira Waheed , M. B. Cruz

We investigate a compact star in the general $F(R)$ gravity. Developing a novel formulation in the spherically symmetric and static space-time with the matter, we confirm that an arbitrary relation between the mass $M$ and the radius $R_s$…

General Relativity and Quantum Cosmology · Physics 2022-10-18 Kota Numajiri , Taishi Katsuragawa , Shin'ichi Nojiri

In this work, the early evolution of low-mass fully convective stars is studied in the context of DHOST (degenerate higher order scalar-tensor) theories of gravity. Although it is known that the hydrostatic equilibrium equation is modified…

General Relativity and Quantum Cosmology · Physics 2023-06-13 Débora Aguiar Gomes , Aneta Wojnar

In the last decade Planck PR4 data together with ground-based experimental data such as, BK18, BAO and CMB lensing, tightened constraint of the tensor to scalar ratio, starting form $r < 0.14$ to $r < 0.032$, while the spectral index lies…

General Relativity and Quantum Cosmology · Physics 2023-08-24 Dalia Saha , Jyoti Prasad Saha , Abhik Kumar Sanyal

Here we propose the extended modified gravity theory named as $f(R,G,\mathcal{T})$ gravity where $R$ is the Ricci scalar, $G$ is the Gauss-Bonnet invariant and $\mathcal{T}$ is the trace of the stress-energy tensor. We derive the…

General Relativity and Quantum Cosmology · Physics 2020-12-02 Ujjal Debnath

The paper presents late time cosmology in $f(Q,T)$ gravity where the dark energy is purely geometric in nature. We start by employing a well motivated $f(Q,T)$ gravity model, $f(Q,T)=mQ^{n}+bT$ where $m,n$ and $b$ are model parameters.…

General Relativity and Quantum Cosmology · Physics 2020-07-06 Simran Arora , S. K. J. Pacif , Snehasish Bhattacharjee , P. K. Sahoo

Within the theoretical framework of some modern unification theories the constants of nature are functions of cosmological time. White dwarfs offer the possibility of testing a possible variation of G and, thus, to place constraints to…

Solar and Stellar Astrophysics · Physics 2015-05-20 L. G. Althaus , A. H. Corsico , S. Torres , P. Loren-Aguilar , J. Isern , E. Garcia-Berro

We develop the reconstruction program for the number of modified gravities: scalar-tensor theory, $f(R)$, $F(G)$ and string-inspired, scalar-Gauss-Bonnet gravity. The known (classical) universe expansion history is used for the explicit and…

High Energy Physics - Theory · Physics 2010-04-06 Shin'ichi Nojiri , Sergei D. Odintsov

The cosmological scalar perturbations of standard matter are investigated in the context of extended teleparallel $f(T)$ gravity theories using the $1+3$ covariant formalism. After a review of the background, gravitational field equations…

General Relativity and Quantum Cosmology · Physics 2020-06-24 Shambel Sahlu , Joseph Ntahompagaze , Amare Abebe , Alvaro de la Cruz-Dombriz , David F. Mota

In this work, we investigate the cosmological dynamics of an anisotropic Universe within the framework of $f(R,T)$ gravity by incorporating pressureless dark matter and the dark energy models. The analysis is carried out in a Bianchi type-I…

General Relativity and Quantum Cosmology · Physics 2026-05-13 S. H. Shekh , N. Myrzakulov , Anirudh Pradhan , M. Zeyauddin
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