English
Related papers

Related papers: Reconstruction of $f(R)$ lagrangian from a massive…

200 papers

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 present a reconstruction technique for models of $f(R)$ gravity from the Chaplygin scalar field in flat de Sitter spacetimes. Exploiting the equivalence between $f(R)$ gravity and scalar-tensor theories, and treating the Chaplygin gas as…

General Relativity and Quantum Cosmology · Physics 2018-02-14 Heba Sami , Neo Namane , Joseph Ntahompagaze , Maye Elmardi , Amare Abebe

We describe a novel procedure to map the field equations of nonlinear Ricci-based metric-affine theories of gravity, coupled to scalar matter described by a given Lagrangian, into the field equations of General Relativity coupled to a…

General Relativity and Quantum Cosmology · Physics 2019-02-27 Victor I. Afonso , Gonzalo J. Olmo , Emanuele Orazi , Diego Rubiera-Garcia

This paper discusses a simple procedure to reconstruct f (R)-gravity models from exact cosmological solutions of the Einstein field equations with a noninteracting classical scalar field-and-radiation background. From the kind of…

General Relativity and Quantum Cosmology · Physics 2017-09-15 Heba Sami , Joseph Ntahompagaze , Amare Abebe

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

We present a novel approach to modified theories of gravity that consists of adding to the Einstein-Hilbert Lagrangian an f(R) term constructed a la Palatini. Using the respective dynamically equivalent scalar-tensor representation, we show…

General Relativity and Quantum Cosmology · Physics 2012-04-26 Tiberiu Harko , Tomi S. Koivisto , Francisco S. N. Lobo , Gonzalo J. Olmo

We study f(R)-gravity with torsion in presence of Dirac massive fields. Using the Bianchi identities, we formulate the conservation laws of the theory and we check the consistency with the matter field equations. Further, we decompose the…

General Relativity and Quantum Cosmology · Physics 2011-05-13 Luca Fabbri , Stefano Vignolo

Following our previous work in [JCAP 1206, 041 (2012)], in this paper, we continue our study of reconstructing $f(R)$ modified gravity models that can be connected to a single scalar field in general relativity via conformal transformation,…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 Taotao Qiu

General relativity characterizes gravity as a geometric property exhibited on spacetime by massive objects while teleparallel gravity achieves the same results, at the level of equations, by taking a torsional perspective of gravity.…

General Relativity and Quantum Cosmology · Physics 2018-01-17 Soumya Chakrabarti , Jackson Levi Said , Gabriel Farrugia

We construct a general stratified scalar theory of gravitation from a field equation that accounts for the self-interaction of the field and a particle Lagrangian, and calculate its post-Newtonian parameters. Using this general framework,…

General Relativity and Quantum Cosmology · Physics 2018-12-07 Diogo P. L. Bragança , José P. S. Lemos

A brief introduction to theories of the gravitational field with a Lagrangian that is a function of the scalar curvature is given. The emphasis will be placed in formal developments, while comparison to observation will be discussed in the…

General Relativity and Quantum Cosmology · Physics 2011-11-14 Santiago Esteban Perez Bergliaffa

In this letter, we consider the theory of $F(R)$ gravity with the lagrangian density $ \pounds = R+\alpha R^2 + \beta R^2 \ln \beta R $. We obtain the constant curvature solutions and find the scalar potential of the gravitational field. We…

General Relativity and Quantum Cosmology · Physics 2016-06-09 J. Sadeghi , H. Farahani

In this paper, we explore a reconstruction scheme in the background of the $f(T,\mathcal{T})$ gravity theory for different cosmological scenarios, where $T$ is the scalar torsion and $\mathcal{T}$ is the trace of the energy-momentum tensor.…

General Relativity and Quantum Cosmology · Physics 2023-10-17 Tuhina Ghorui , Prabir Rudra , Farook Rahaman

In this paper, we explore the nature of scalar field potential in $f(R, R_{\alpha\beta} R^{\alpha\beta},\phi)$ gravity using a well-motivated reconstruction scheme for flat FRW geometry. The beauty of this scheme lies in the assumption that…

General Relativity and Quantum Cosmology · Physics 2017-01-25 M. Zubair , Farzana Kousar , Saira Waheed

The duality between a higher curvature $f(R)$ gravity model and a scalar-tensor theory helps to bring out the role of the additional degree of freedom originating from the higher derivative terms in the gravity action. Such a degree of…

General Relativity and Quantum Cosmology · Physics 2024-06-21 Hitender Kumar , Tanmoy Paul , Soumitra SenGupta

General relativity (GR) characterizes gravity as a geometric properly exhibited as curvature on spacetime. Teleprallelism describes gravity through torsional properties, and can reproduce GR at the level of equations. Similar to f(R)…

General Relativity and Quantum Cosmology · Physics 2017-12-21 Jackson Levi Said

Teleparallel description of gravity theories where the gravity is mediated through the tetrad field and consequent torsion provide an alternative route to explain the late time cosmic speed up issue. Generalization of the teleparallel…

General Relativity and Quantum Cosmology · Physics 2025-01-10 S. K. Tripathy , Sasmita Pal , B. Mishra

The role of torsion and a scalar field $\phi$ in gravitation in the background of a particular class of the Riemann-Cartan geometry is considered here. Some times ago, a Lagrangian density with Lagrange multipliers has been proposed by the…

Astrophysics · Physics 2008-02-18 Prasanta Mahato

We consider f(R,T) modified theories of gravity, where the gravitational Lagrangian is given by an arbitrary function of the Ricci scalar R and of the trace of the stress-energy tensor T. We obtain the gravitational field equations in the…

General Relativity and Quantum Cosmology · Physics 2011-07-14 Tiberiu Harko , Francisco S. N. Lobo , Shin'ichi Nojiri , Sergei D. Odintsov

In this work, we investigate the cosmological dynamics of the $f(R, \mathcal{L}_m)$ gravity framework with a particular focus on the contributions of the scalar field. Considering a functional form that includes linear and exponential…

General Relativity and Quantum Cosmology · Physics 2026-04-01 Y. Kalpana Devi , Rahul Bhagat , B. Mishra
‹ Prev 1 2 3 10 Next ›