English
Related papers

Related papers: Herglotz-type $f(R,T)$ gravity

200 papers

The evolutionary behavior of the Universe has been analysed through the dynamical system analysis in $f(T,B,T_G,B_G)$ gravity, where $T$, $B$, $T_G$, and $B_G$ respectively represent torsion, boundary term, teleparallel Gauss-Bonnet term…

General Relativity and Quantum Cosmology · Physics 2025-01-10 S. A. Kadam , B. Mishra

We extend the formalism of the Einstein-Hilbert unimodular gravity in the context of modified $F(R)$ gravity. After appropriately modifying the Friedmann-Robertson-Walker metric in a way that it becomes compatible to the unimodular…

General Relativity and Quantum Cosmology · Physics 2016-06-01 S. Nojiri , S. D. Odintsov , V. K. Oikonomou

The $f(R)$ gravity can be cast into the form of a scalar-tensor theory, and scalar degree of freedom can be suppressed in high-density regions by the chameleon mechanism. In this article, for the general $f(R)$ gravity, using a…

Cosmology and Nongalactic Astrophysics · Physics 2018-01-04 Tan Liu , Xing Zhang , Wen Zhao

The late-time acceleration of the universe remains one of the most significant open problems in modern cosmology. Modified gravity frameworks such as $f(T)$ gravity provide a geometric alternative to dark energy by attributing cosmic…

General Relativity and Quantum Cosmology · Physics 2026-05-07 Anirudh Pradhan , S. A. Salve , V. B. Raut , S. H. Shekh

In this paper, I consider a $f(R, G, T)$ modified gravity model where $R$ represents the Ricci scalar, $G$ denotes the Gauss-Bonnet invariant, and $T$ signifies the trace of the stress-energy tensor. This model is coupled with two distinct…

General Relativity and Quantum Cosmology · Physics 2024-09-04 Farzad Milani

The field equations of a generalized $f(R)$ type gravity model, in which there is an arbitrary coupling between matter and geometry, are obtained. The equations of motion for test particles are derived from a variational principle in the…

General Relativity and Quantum Cosmology · Physics 2009-05-26 T. Harko

We generalize previous work by considering a novel gravitational model with an action given by an arbitrary function of the Ricci scalar, the matter Lagrangian density, a scalar field and a kinetic term constructed from the gradients of the…

General Relativity and Quantum Cosmology · Physics 2013-02-06 Tiberiu Harko , Francisco S. N. Lobo , Olivier Minazzoli

In this paper, we introduce bulk viscosity in the formalism of modified gravity theory in which the gravitational action contains a general function $f(R,T)$, where $R$ and $T$ denote the curvature scalar and the trace of the…

General Relativity and Quantum Cosmology · Physics 2015-03-02 C. P. Singh , Pankaj Kumar

We search for viable f(R) theories of gravity, making use of the equivalence between such theories and scalar-tensor gravity. We find that models can be made consistent with solar system constraints either by giving the scalar a high mass…

Astrophysics · Physics 2008-11-26 Thomas Faulkner , Max Tegmark , Emory F. Bunn , Yi Mao

Harko and Moraes claim that in $f(R,T)$ gravity with $f(R,T)=f_1(R)+f_2(T)$, the term $f_2(T)$ cannot be incorporated in the matter Lagrangian ${\cal L}_m$. A careful examination of their Comment finds that they have made several dubious…

General Relativity and Quantum Cosmology · Physics 2020-06-24 Sarah B. Fisher , Eric D. Carlson

In this paper, we have considered a quadratic variation of the deceleration parameter ($q$) as a function of cosmic time ($t$) which describes a smooth transition from the decelerating phase of the Universe to an accelerating one and also…

General Relativity and Quantum Cosmology · Physics 2022-06-30 Ritika Nagpal , Shibesh Kumar Jas Pacif

We explore the existence of wormholes in the context of $f(R,T)$ gravity. The $f(R,T)$ theory is a curvature-matter coupled modified gravity that depends on an arbitrary function of the Ricci scalar $R$ and the trace of the stress-energy…

General Relativity and Quantum Cosmology · Physics 2023-05-24 Ayan Banerjee , Takol Tangphati , Anirudh Pradhan

In this paper, we have explored the field equations of f(T, B) gravity as an extension of teleparallel gravity in an isotropic and homogeneous space time. In the basic formalism developed, the dynamical parameters are derived by…

General Relativity and Quantum Cosmology · Physics 2024-09-27 S. A. Kadam , Jackson Levi Said , B. Mishra

We consider the $f(R,T)$ theory, where $R$ is the scalar curvature and $T$ is the trace of energy-momentum tensor, as an effective description for the holographic and new agegraphic dark energy and reconstruct the corresponding $f(R,T)$…

General Relativity and Quantum Cosmology · Physics 2013-10-04 M. Sharif , M. Zubair

This paper studies a generic fourth-order theory of gravity with Lagrangian density $f(R,R_c^2,R_m^2, \mathscr{L}_m)$. By considering explicit $R^2$ dependence and imposing the "coherence condition" $f_{R^2}\!=\!f_{R_m^2}\!=\!…

General Relativity and Quantum Cosmology · Physics 2015-07-14 David Wenjie Tian , Ivan Booth

We apply cosmological reconstruction methods to the $f(R,T)$ modified gravity, in its recently developed scalar-tensor representation. We do this analysis assuming a perfect fluid in a Friedmann-Lema\^{i}tre-Robsertson-Walker (FLRW)…

General Relativity and Quantum Cosmology · Physics 2024-07-24 Tiago B. Gonçalves , João Luís Rosa , Francisco S. N. Lobo

The standard cosmological model, rooted in General Relativity (GR), has achieved remarkable success, yet it still faces unresolved issues like the nature of dark matter, dark energy, and the Hubble tension. These challenges might imply the…

General Relativity and Quantum Cosmology · Physics 2025-05-13 Valentina Danieli , Antonio De Felice

The $f(T)$ gravity is one of the extensions of teleparallel equivalent of general relativity, in which more general functions of the torsion scalar $T$ can be described. With the proposed functional form of $f(T) = \alpha T - \beta u^{-n} +…

General Relativity and Quantum Cosmology · Physics 2026-04-14 Suraj Kumar Behera , S. A. Kadam , Pratik P. Ray , B. Mishra

Here we analysed a particular type of $F(R)$ gravity, the so-called exponential gravity which includes an exponential function of the Ricci scalar in the action. Such term represents a correction to the usual Hilbert-Einstein action. By…

General Relativity and Quantum Cosmology · Physics 2018-01-17 Sergei D. Odintsov , Diego Saez-Chillon Gomez , German S. Sharov

The review is devoted to consideration of possible observational consequences of modified gravity theories, suggested for explanation of the contemporary accelerated expansion of the universe. The major attention is paid to F(R)-models. It…

General Relativity and Quantum Cosmology · Physics 2019-11-11 Elena Arbuzova