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A plane symmetric Bianchi-I model is explored in $f(R,T)$ gravity, where $R$ is the Ricci scalar and $T$ is the trace of energy-momentum tensor. The solutions are obtained with the consideration of a specific Hubble parameter which yields a…

General Relativity and Quantum Cosmology · Physics 2020-03-23 Vijay Singh , Aroonkumar Beesham

We review some recent developments in the conformal gravity theory that has been advanced as a candidate alternative to standard Einstein gravity. As a quantum theory the conformal theory is both renormalizable and unitary, with unitarity…

High Energy Physics - Theory · Physics 2015-05-27 Philip D. Mannheim

We derive the Hamiltonian function for extended teleparallel theories of gravity in their covariant formulation. In particular, we present the Hamiltonian for $f(T)$ gravity and New General Relativity. From this, we obtain the related…

General Relativity and Quantum Cosmology · Physics 2025-03-21 Francesco Bajardi , Daniel Blixt , Salvatore Capozziello

In the context of f(R,T) theories of gravity, we study the evolution of scalar cosmological perturbations in the metric formalism. According to restrictions on the background evolution, a specific model within these theories is assumed in…

General Relativity and Quantum Cosmology · Physics 2013-06-20 F. G. Alvarenga , A. de la Cruz-Dombriz , M. J. S. Houndjo , M. E. Rodrigues , D. Sáez-Gómez

Teleparallel gravity and its popular generalization $f(T)$ gravity can be formulated as fully invariant (under both coordinate transformations and local Lorentz transformations) theories of gravity. Several misconceptions about teleparallel…

General Relativity and Quantum Cosmology · Physics 2019-09-25 M. Krssak , R. J. van den Hoogen , J. G. Pereira , C. G. Boehmer , A. A. Coley

We present a multi-epoch test of f(T) gravity with nonminimal torsion-matter coupling, combining early- and late-Universe observations. At the MeV scale, Big-Bang Nucleosynthesis constrains the fractional variation of the weak freeze-out…

Cosmology and Nongalactic Astrophysics · Physics 2026-01-27 Yahia Al-Omar , Majida Nahili , Nidal Chamoun

Finding spherically symmetric exact solutions in modified gravity is usually a difficult task. In this paper we use the Noether's symmetry approach for a modified Teleparallel theory of gravity labelled as $f(T,B)$ gravity where $T$ is the…

General Relativity and Quantum Cosmology · Physics 2019-12-02 Sebastian Bahamonde , Ugur Camci

We construct a family of viable scalar-tensor models of dark energy (DE) which possess a phase of late-time acceleration preceded by a standard matter era, while at the same time satisfying the local gravity constraints (LGC). The coupling…

Astrophysics · Physics 2008-11-26 Shinji Tsujikawa , Kotub Uddin , Shuntaro Mizuno , Reza Tavakol , Jun'ichi Yokoyama

We study particle production aspect in the flat FRW universe in the framework of $f(T)$ gravity. The matter is minimally coupled with the gravity and an exact power-law solution is obtained by solving the Friedmann equations, and matter is…

General Physics · Physics 2013-03-26 M. R. Setare , M. J. S. Houndjo

In this paper we investigate charged static black holes in 4D for generalized teleparallel models of gravity, based on torsion as the geometric object for describing gravity according to the equivalence principle. As a motivated idea, we…

General Relativity and Quantum Cosmology · Physics 2013-12-02 M. E. Rodrigues , M. J. S. Houndjo , J. Tossa , D. Momeni , R. Myrzakulov

In this study, we explore the cosmological implications of a modified gravity theory characterized by the function \( f(R, \Sigma, T) \), where \( R \) is the Ricci scalar, \( \Sigma \) represents a geometric deformation term, and \( T \)…

General Relativity and Quantum Cosmology · Physics 2026-01-06 N. Myrzakulov , S. H. Shekh , S. R. Bhoyar , Anirudh Pradhan

The present paper examines the validity of energy bounds in a modified theory of gravity involving non-minimal coupling of torsion scalar and perfect fluid matter. In this respect, we formulate the general inequalities of energy conditions…

General Relativity and Quantum Cosmology · Physics 2015-02-11 M. Zubair , Saira Waheed

We present a novel theory of gravity by considering an extension of symmetric teleparallel gravity. This is done by introducing, in the framework of the metric-affine formalism, a new class of theories where the nonmetricity $Q$ is…

General Relativity and Quantum Cosmology · Physics 2018-10-31 Tiberiu Harko , Tomi S. Koivisto , Francisco S. N. Lobo , Gonzalo J. Olmo , Diego Rubiera-Garcia

We investigate Einstein theories of gravity, coupled to a scalar field \vphi and point-like matter, which are characterized by a scalar field-dependent matter coupling function e^{H(\vphi)}. We show that under mild constraints on the form…

General Relativity and Quantum Cosmology · Physics 2014-11-18 M. Cadoni , M. Casula

By using a bottom-up reconstruction technique for non-minimally coupled scalar-tensor theories, we realize the Einstein frame attractor cosmologies in the $\Omega (\phi)$-Jordan frame. For our approach, what is needed for the reconstruction…

General Relativity and Quantum Cosmology · Physics 2018-04-04 S. D. Odintsov , V. K. Oikonomou

We investigate modified theories of gravity in the context of teleparallel geometries with possible Gauss-Bonnet contributions. The possible coupling of gravity with the trace of the energy-momentum tensor is also taken into account. This…

General Relativity and Quantum Cosmology · Physics 2018-06-25 Sebastian Bahamonde , Christian G. Boehmer

This article presents cosmological models that arise in a subclass of $f(R,T)=f(R)+f(T)$ gravity models, with different $f(R)$ functions and fixed $T$-dependence. That is, the gravitational lagrangian is considered as $f(R,T)=f(R)+\lambda…

General Relativity and Quantum Cosmology · Physics 2018-09-18 P. K. Sahoo , P. H. R. S. Moraes , Parbati Sahoo , Binaya K. Bishi

Teleparallel based cosmological models provide a description of gravity in which torsion is the mediator of gravitation. Several extensions have been made within the so-called Teleparallel equivalent of general relativity which is…

General Relativity and Quantum Cosmology · Physics 2023-01-18 L. K. Duchaniya , S. A. Kadam , Jackson Levi Said , B. Mishra

We analyse f(R) modifications of Einstein's gravity as dark energy models in the light of their connection with chameleon theories. Formulated as scalar-tensor theories, the f(R) theories imply the existence of a strong coupling of the…

Astrophysics · Physics 2009-02-23 Philippe Brax , Carsten van de Bruck , Anne-Christine Davis , Douglas J. Shaw

Teleparallel theories of gravity have a long history. They include a special case referred to as the Teleparallel Equivalent of General Relativity (TEGR, aka GR$_{\|}$). Recently this theory has been generalized to f(T) gravity. Tight…

General Relativity and Quantum Cosmology · Physics 2013-08-01 Yen Chin Ong , Keisuke Izumi , James M. Nester , Pisin Chen
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