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Related papers: $f(T)$ models with phantom divide line crossing

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We investigate alternative candidates to dark energy that can explain the current state of the universe in the framework of the generalized teleparallel theory of gravity $f(T)$ where $T$ denotes the torsion scalar. To achieve this, we…

General Physics · Physics 2020-08-26 A. E. Godonou , Ines G. Salako , M. J. S. Houndjo , Etienne Baffou , Joel Tossa

In this work we present a further investigation about Teleparallel Gravity Cosmology. We demonstrate that according the current astrophysical data (CC+Pantheon+BAO samplers with late universe measurements SH0ES+H0LiCOW), an $f(T,B)$ theory…

General Relativity and Quantum Cosmology · Physics 2021-05-07 Celia Escamilla-Rivera , Jackson Levi Said

In this paper, we explore the model of $f(Q,T)$ gravity, an extension of symmetric teleparallel gravity where the nonmetricity scalar $Q$ is non-minimally coupled to the trace of the energy-momentum tensor $T$. To ensure general covariance…

General Relativity and Quantum Cosmology · Physics 2025-09-09 Rahul Bhagat , Santosh V. Lohakare , B. Mishra

We consider the Chiral cosmological model consisting of two scalar fields minimally coupled to gravity. In the context of a Friedmann--Lema\^{\i}tre--Robertson--Walker (FLRW) space-time, and for massless fields in the presence of a…

General Relativity and Quantum Cosmology · Physics 2021-06-09 Nikolaos Dimakis , Andronikos Paliathanasis

Conditions needed to cross the phantom divide line in an interacting holographic dark energy model in closed Friedmann- Robertson-Walker universe are discussed. The probable relationship between this crossing and the coincidence problem is…

General Relativity and Quantum Cosmology · Physics 2009-07-24 H. Mohseni Sadjadi

In this study, we explore the dynamics of the universe using a modified gravity model represented by $f(R, G, T)$, where $R$ is the Ricci scalar, $G$ is the Gauss-Bonnet invariant, and $T$ is the trace of the stress-energy tensor. The model…

General Relativity and Quantum Cosmology · Physics 2025-03-27 Farzad Milani

Recently a lot of attention has been given to building dark energy models in which the equation-of-state parameter $w$ can cross the phantom divide $w=-1$. However, to our knowledge, these models with crossing the phantom divide only…

Astrophysics · Physics 2008-11-26 Hao Wei , Rong-Gen Cai

A scalar field model with non-minimal derivative coupling to gravity is considered. It is shown that although in the absence of matter and potential the phantom divide line crossing is forbidden, but for the power law potential and in the…

General Relativity and Quantum Cosmology · Physics 2011-09-07 H. Mohseni Sadjadi

This cosmological model is a study of modified $f(Q,T)$ theory of gravity which was recently proposed by Xu {\it et al.} (Eur. Phys. J. C {\bf 79}, 708 (2019)). In this theory of gravity, the action contains an arbitrary function $f(Q,T)$…

General Physics · Physics 2021-09-03 Anirudh Pradhan , Archana Dixit

In this work, we investigate the bouncing behavior of the universe within the framework of $f(R,L_m)$ gravity, using a simple form of $f(R,L_m)=\frac{R}{2}+L_m^\gamma$ (where $\gamma$ is a free model parameter) as previously studied. The…

General Relativity and Quantum Cosmology · Physics 2024-03-29 M. Koussour , N. Myrzakulov , Javlon Rayimbaev , Alnadhief H. A. Alfedeel , H. M. Elkhair

The dynamical aspects of some accelerating models are investigated in the framework of an extension of symmetric teleparllel gravity dubbed as f(Q,T) gravity. In this gravity theory, the usual Ricci tensor in the geometrical action is…

General Relativity and Quantum Cosmology · Physics 2021-07-28 Laxmipriya Pati , B. Mishra , S. K. Tripathy

Starting from the original Einstein action, sometimes called the Gamma squared action, we propose a new setup to formulate modified theories of gravity. This can yield a theory with second order field equations similar to those found in…

General Relativity and Quantum Cosmology · Physics 2021-07-14 Christian G. Boehmer , Erik Jensko

In this paper, we have introduced a new $f(R)$ gravity model as an attempt to have a model with more parametric control, so that the model can be used to explain the existing problems as well as to explore new directions in physics of…

General Relativity and Quantum Cosmology · Physics 2020-12-03 Dhruba Jyoti Gogoi , Umananda Dev Goswami

It is known that scalar-tensor theory of gravity admits regular crossing of the phantom divide line $w_{\DE}=-1$ for dark energy, and existing viable models of present dark energy for its particular case -- $f(R)$ gravity -- possess one…

Cosmology and Nongalactic Astrophysics · Physics 2011-06-08 Hayato Motohashi , Alexei A. Starobinsky , Jun'ichi Yokoyama

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

We identify the class of f(R) dark energy models which have a viable cosmology, i.e. a matter dominated epoch followed by a late-time acceleration. The deviation from a LambdaCDM model (f=R-Lambda) is quantified by the function…

Astrophysics · Physics 2010-04-28 Luca Amendola , Shinji Tsujikawa

We use observations related to the variation of fundamental constants, in order to impose constraints on the viable and most used $f(T)$ gravity models. In particular, for the fine-structure constant we use direct measurements obtained by…

General Relativity and Quantum Cosmology · Physics 2017-04-18 Rafael C. Nunes , Alexander Bonilla , Supriya Pan , Emmanuel N. Saridakis

We investigate the cosmological applications of $F(T,T_G)$ gravity, which is a novel modified gravitational theory based on the torsion invariant $T$ and the teleparallel equivalent of the Gauss-Bonnet term $T_{G}$. $F(T,T_{G})$ gravity…

General Relativity and Quantum Cosmology · Physics 2014-10-29 Georgios Kofinas , Emmanuel N. Saridakis

We construct an extension of f(T) gravity with the inclusion of a non-minimal torsion-matter coupling in the action. The resulting theory is a novel gravitational modification, since it is different from both f(T) gravity, as well as from…

General Relativity and Quantum Cosmology · Physics 2014-07-01 Tiberiu Harko , Francisco S. N. Lobo , G. Otalora , Emmanuel N. Saridakis

We develop the effective field theory approach to torsional modified gravities, a formalism that allows for the systematic investigation of the background and perturbation levels separately. Starting from the usual effective field theory…

General Relativity and Quantum Cosmology · Physics 2018-10-03 Chunlong Li , Yong Cai , Yi-Fu Cai , Emmanuel N. Saridakis