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Related papers: Construction of cosmologically viable f(G) gravity…

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In this paper, we carry out a study of viable cosmological models in $f(R)$-gravity at the background level. We use observable parameters like $\Omega$ and $\gamma$ to form autonomous system of equations and show that the models under…

Cosmology and Nongalactic Astrophysics · Physics 2010-05-28 Amna Ali , Radouane Gannouji , M. Sami , Anjan A. Sen

We propose the Gauss-Bonnet dark energy model inspired by string/M-theory where standard gravity with scalar contains additional scalar-dependent coupling with Gauss-Bonnet invariant. It is demonstrated that effective phantom (or…

High Energy Physics - Theory · Physics 2009-09-17 Shin'ichi Nojiri , Sergei D. Odintsov , Misao Sasaki

The following issue is addressed: how the addition of a Gauss-Bonnet term (generically coming from most fundamental theories, as string and M theories), to a viable model, can change the specific properties, and even the physical nature, of…

General Relativity and Quantum Cosmology · Physics 2016-06-15 Anna Escofet , Emilio Elizalde

Currently, in order to explain the accelerated expansion phase of the universe, several alternative approaches have been proposed, among which the most common are dark energy models and alternative theories of gravity. Although these…

General Relativity and Quantum Cosmology · Physics 2021-08-24 I. S. Farias , P. H. R. S. Moraes

The starting point in this note is $f(R)$ modified gravity in a cosmological setting. We assume a spatially flat Universe to describe late-time cosmology and the perfect-fluid equation of state $p=\omega\rho$ to model the hypothesized dark…

General Relativity and Quantum Cosmology · Physics 2017-06-13 Peter K. F. Kuhfittig

We explore an extension of the symmetric teleparallel gravity denoted the $f(Q)$ theory, by considering a function of the nonmetricity invariant $Q$ as the gravitational Lagrangian. Some interesting properties could be found in the $f(Q)$…

General Relativity and Quantum Cosmology · Physics 2019-06-24 Jianbo Lu , Xin Zhao , Guoying Chee

In this paper, we consider a gravitational action containing a combination of the Ricci scalar, $R$, and the topological Gauss--Bonnet term, $G$. Specifically, we study the cosmological features of a particular class of modified gravity…

General Relativity and Quantum Cosmology · Physics 2023-03-15 Francesco Bajardi , Rocco D'Agostino

In the present article, we developed a dynamical system in the context of modified $f(R,G,T)$ gravity, where $R$, $G$ and $T$ are Ricci scalar, Gauss-Bonnet term and energy-momentum tensor respectively. Development of the dynamical system…

General Relativity and Quantum Cosmology · Physics 2025-05-30 Elangbam Chingkheinganba Meetei , S. Surendra Singh

Using a correspondence between the f(T)-gravity with the power-law entropy corrected version of the holographic dark energy model, we reconstruct the holographic f(T)-gravity model with power-law entropy correction. We fit the model…

General Relativity and Quantum Cosmology · Physics 2013-11-06 K. Karami , S. Asadzadeh , A. Abdolmaleki , Z. Safari

Dark energy cosmology is considered in a modified Gauss-Bonnet model of gravity with and without a scalar field. It is shown that these generalizations of General Relativity endow it with a very rich cosmological structure: it may naturally…

General Relativity and Quantum Cosmology · Physics 2015-05-18 Emilio Elizalde , Ratbay Myrzakulov , Valery V. Obukhov , Diego Sáez-Gómez

Working within the theory of modified Gauss-Bonnet gravity, we show that FLRW--like power--law solutions only exist for a very special class of f(G)theories. Furthermore, we point out that any transition from decelerated to accelerated…

General Relativity and Quantum Cosmology · Physics 2009-06-30 Naureen Goheer , Rituparno Goswami , Peter K. S. Dunsby , Kishore Ananda

The observed accelerated cosmic expansion can be a signature of fourth\,-\,order gravity theories, where the acceleration of the Universe is a consequence of departures from Einstein General Relativity, rather than the sign of the existence…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 Vincenzo F. Cardone , Stefano Camera , Antonaldo Diaferio

We investigate the cosmological applications of new gravitational scalar-tensor theories, which are novel modifications of gravity possessing 2+2 propagating degrees of freedom, arising from a Lagrangian that includes the Ricci scalar and…

General Relativity and Quantum Cosmology · Physics 2016-06-22 Emmanuel N. Saridakis , Minas Tsoukalas

Various cosmological models in frames of $F(T)$ gravity are considered. The general scheme of constructing effective dark energy models with various evolution is presented. It is showed that these models in principle are compatible with…

General Relativity and Quantum Cosmology · Physics 2015-06-16 Artyom V. Astashenok

We perform observational confrontation and cosmographic analysis of $f(T,T_G)$ gravity and cosmology. This higher-order torsional gravity is based on both the torsion scalar, as well as on the teleparallel equivalent of the Gauss--Bonnet…

General Relativity and Quantum Cosmology · Physics 2024-10-15 Harshna Balhara , J. K. Singh , Shaily , Emmanuel N. Saridakis

The $f(T,T_G)$ class of gravitational modification, based on the quadratic torsion scalar $T$, as well as on the new quartic torsion scalar $T_G$ which is the teleparallel equivalent of the Gauss-Bonnet term, is a novel theory, different…

General Relativity and Quantum Cosmology · Physics 2014-08-19 Georgios Kofinas , Genly Leon , Emmanuel N. Saridakis

We investigate the logarithmic form of $f(Q,T)$ gravity with two different choices of matter Lagrangian such as: $\mathcal{L}_m = p$ and $\mathcal{L}_m = -\rho$. The parameters of the model has been constrained using Cosmic Chronometers…

General Relativity and Quantum Cosmology · Physics 2025-09-18 Rahul Bhagat , I. V. Fomin , B. Mishra

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 show that f(R)-gravity can, in general, give rise to cosmological viable models compatible with a matter-dominated epoch evolving into a late accelerated phase. We discuss the various representations of f(R)-gravity as an ideal fluid or…

Astrophysics · Physics 2008-11-26 S. Capozziello , S. Nojiri , S. D. Odintsov , A. Troisi

We establish constraints on $f(T)$ gravity by considering the possibility of a scenario that supports a phantom crossing of the equation of state parameter $\omega_{DE}$. After determining the viable parameter space of the model, while…

Cosmology and Nongalactic Astrophysics · Physics 2023-06-23 F. B. M. dos Santos