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

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We investigate the cosmological solutions of the $f(T)$ gravity theory using the method of dynamical systems. For this purpose a general form of the $f(T)$ function is considered and four conditions are defined that they have to satisfy in…

General Relativity and Quantum Cosmology · Physics 2017-12-12 Behrouz Mirza , Fatemeh Oboudiat

We perform a dynamical system analysis of Myrzakulov or F(R, T) gravity, which is a subclass of affinely connected metric theories, where ones uses a specific but non-special connection, which allows for non-zero curvature and torsion…

General Relativity and Quantum Cosmology · Physics 2022-11-30 G. Papagiannopoulos , Spyros Basilakos , Emmanuel N. Saridakis

Dark energy models with a single scalar field cannot cross the equation of state divide set by a cosmological constant. More general models that allow crossing require additional degrees of freedom to ensure gravitational stability. We show…

Astrophysics · Physics 2008-12-01 Wenjuan Fang , Wayne Hu , Antony Lewis

We present a novel reconstruction method of $f(T)$ teleparallel gravity from phenomenological parameterizations of the deceleration parameter or other alternatives. This can be used as a toolkit to produce viable modified gravity scenarios…

General Relativity and Quantum Cosmology · Physics 2019-10-29 W. El Hanafy , G. G. L. Nashed

In this study, FRW cosmology in modified gravity containing arbitrary function $f(R)$ is taken into consideration when our action are coupled with Weyl tensor. It is indicated that the bouncing solution emerges in the model while the…

General Physics · Physics 2015-03-31 Mohammad Ghanaatian , Farzad Milani

We propose a new exponential f(R) gravity model with f(R)=(R-\lambda c)e^{\lambda(c/R)^n} and n>3, \lambda\geq 1, c>0 to explain late-time acceleration of the universe. At the high curvature region, the model behaves like the \LambdaCDM…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Qiang Xu , Bin Chen

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

In this paper, we have performed the dynamical system analysis of $f(T)$ gravity cosmological models at both background and perturbation levels. We have presented three models pertaining to three distinct functional forms of $f(T)$. The…

General Relativity and Quantum Cosmology · Physics 2024-03-20 L. K. Duchaniya , Kanika Gandhi , B. Mishra

We present a systematic analysis of the dynamics of flat Friedmann-Lema\^{i}tre-Robertson-Walker cosmological models with radiation and dust matter in generalized teleparallel $f(T)$ gravity. We show that the cosmological dynamics of this…

General Relativity and Quantum Cosmology · Physics 2017-09-05 Manuel Hohmann , Laur Jarv , Ulbossyn Ualikhanova

We reconstruct different f(R)-gravity models corresponding to the polytropic, standard Chaplygin, generalized Chaplygin, modified Chaplygin and modified variable Chaplygin gas dark energy models. We also obtain the equation of state…

General Physics · Physics 2015-03-17 K. Karami , M. S. Khaledian

We construct cosmological models with two scalar fields, which has the structure as in the ghost condensation model or k-essence model. The models can describe the stable phantom crossing, which should be contrasted with one scalar tensor…

High Energy Physics - Theory · Physics 2015-06-04 Rio Saitou , Shin'ichi Nojiri

A pair of fractal gravity models can be derived from the spatial interaction models based on entropy maximizing principle and allometric scaling law. The models can be expressed as dual form in mathematics and are important for analyzing…

Physics and Society · Physics 2023-08-09 Yanguang Chen

Here, we peruse cosmological usage of the most promising candidates of dark energy in the framework of f(R) theory. We reconstruct the different f(R) modified gravity models in the spatially flat FRW universe according to the ordinary and…

General Relativity and Quantum Cosmology · Physics 2011-07-18 K. Karami , M. S. Khaledian

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

Statefinder diagnostic is a convenient method that can differentiate between the various dark energy models. In this article, we analyze the statefinder parameters in symmetric teleparallel cosmology. The $f(Q)$ gravity theory is an…

General Relativity and Quantum Cosmology · Physics 2022-06-27 Raja Solanki , P. K. Sahoo

We present a novel approach for reconstructing the $f(Q)$ gravitational theory using parameterizations of the deceleration parameter or alternative options. This method enables the development of modified gravity scenarios that align with…

General Relativity and Quantum Cosmology · Physics 2025-02-26 G. G. L. Nashed

Motivated by conjectures about near-horizon dynamics in quantum gravity, we search for lines of perturbatively accessible fixed points emanating from models of $N$ free fermions. Through two loops we find a new class of models, apart from…

High Energy Physics - Theory · Physics 2024-08-23 Sidan A , Tom Banks

Dynamics of an anisotropic universe is studied in $f(R,T)$ gravity using a rescaled functional $f(R,T)$. Three models have been constructed assuming a power law expansion of the universe. Physical features of the models are discussed. The…

General Relativity and Quantum Cosmology · Physics 2018-06-06 B. Mishra , S. Tarai , S. K. Tripathy

We present an extension of $f(T)$ gravity, allowing for a general coupling of the torsion scalar $T$ with the trace of the matter energy-momentum tensor $\mathcal{T}$. The resulting $f(T,\mathcal{T})$ theory is a new modified gravity, since…

General Relativity and Quantum Cosmology · Physics 2014-12-12 Tiberiu Harko , Francisco S. N. Lobo , G. Otalora , Emmanuel N. Saridakis

In this work, we consider an emergent universe in generalized gravity theories like the chameleon, f(R) and f(T) gravities. We reconstruct the potential of the chameleon field under the emergent scenario of the universe and observe its…

General Relativity and Quantum Cosmology · Physics 2011-07-04 Surajit Chattopadhyay , Ujjal Debnath