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Related papers: Late-Time Cosmology of Scalar-Coupled $f(R, \mathc…

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In this short note we present the dynamics of a general scalar-tensor model, and in particular a scalar Einstein-Gauss-Bonnet model with a non-minimal coupling between gravity and the kinetic term of the scalar field. For the sake of…

General Relativity and Quantum Cosmology · Physics 2021-10-04 Fotis Fronimos

In this work we present the late-time behaviour of the Universe in the context of Einstein-Gauss-Bonnet gravitational theory. The theory involves a scalar field, which represents low-effective quantum corrections, assisted by a function…

General Relativity and Quantum Cosmology · Physics 2022-04-19 S. A. Venikoudis , K. V. Fasoulakos , F. P. Fronimos

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 this work, the $f(\mathcal{G},T)$ theory of gravity is recast in terms of the $\phi$ and $\psi$ fields within the scalar-tensor formulation, where $\mathcal{G}$ is the Gauss-Bonnet term and $T$ denotes the trace of the energy-momentum…

General Relativity and Quantum Cosmology · Physics 2023-12-20 Adam Z. Kaczmarek , Dominik Szczęśniak

A Gauss-Bonnet (GB) coupled scalar field $\phi$, responsible for the late-time cosmic acceleration and interacting with a coherent scalar field $\psi$ through an interaction potential $W(\phi,\psi)$, is considered from the point of view of…

General Relativity and Quantum Cosmology · Physics 2026-04-13 Saddam Hussain , Simran Arora , Yamuna Rana , Benjamin Rose , Anzhong Wang

Our paper introduces a new theoretical framework called the Fractional Einstein--Gauss--Bonnet scalar field cosmology, which has important physical implications. Using fractional calculus to modify the gravitational action integral, we…

Cosmology and Nongalactic Astrophysics · Physics 2024-12-12 Bayron Micolta-Riascos , Alfredo D. Millano , Genly Leon , Byron Droguett , Esteban González , Juan Magaña

We study the dynamics of the field equations in a five-dimensional spatially flat Friedmann-Lema\^itre-Robertson-Walker metric in the context of a Gauss-Bonnet-Scalar field theory where the quintessence scalar field is coupled to the…

General Relativity and Quantum Cosmology · Physics 2024-07-29 Alfredo D. Millano , Claudio Michea , Genly Leon , Andronikos Paliathanasis

We study $f(R)$ gravity models in the language of scalar-tensor theories. The correspondence between $f(R)$ gravity and scalar-tensor theories is revisited since $f(R)$ gravity is a subclass of Brans-Dicke models, with a vanishing coupling…

General Relativity and Quantum Cosmology · Physics 2017-06-28 Joseph Ntahompagaze , Amare Abebe , Manasse Mbonye

Several models within the framework of Einstein-Gauss-Bonnet gravities are considered with regard their late-time phenomenological viability. The models contain a non-minimally coupled scalar field and satisfy a constraint on the scalar…

General Relativity and Quantum Cosmology · Physics 2025-03-25 S. D. Odintsov , V. K. Oikonomou , German S. Sharov

We study the dynamics of the field equations in a four-dimensional isotropic and homogeneous spatially flat Friedmann--Lema\^{\i}tre--Robertson--Walker geometry in the context of Einstein-Gauss-Bonnet theory with a matter source and a…

General Relativity and Quantum Cosmology · Physics 2023-08-02 Alfredo D. Millano , Genly Leon , Andronikos Paliathanasis

We study the special class of the exact solutions in cosmological models based on the Generalized Scalar-Tensor Gravity with non-minimal coupling of a scalar field to the Ricci scalar and to the Gauss-Bonnet scalar in 4D Friedmann universe…

General Relativity and Quantum Cosmology · Physics 2019-07-17 Igor V. Fomin , Sergey V. Chervon

In this paper, we study the dynamical behaviour of the Universe in the $F(R,G)$ theory of gravity, where $R$ and $G$ respectively denote the Ricci scalar and Gauss-Bonnet invariant. Our wide analysis encompasses the energy conditions,…

General Relativity and Quantum Cosmology · Physics 2022-04-22 Santosh V. Lohakare , S. K. Tripathy , B. Mishra

We study the dynamics of the interacting models between the Gauss-Bonnet (GB) coupled scalar field and the dark matter fluid in a homogeneous and isotropic background. A key feature of GB coupling models is the varying speed of…

General Relativity and Quantum Cosmology · Physics 2024-11-28 Saddam Hussain , Simran Arora , Yamuna Rana , Benjamin Rose , Anzhong Wang

A scalar-tensor theory of gravity is considered wherein the gravitational coupling $G$ and the speed of light $c$ are admitted as space-time functions and combine to form the definition of the scalar field $\phi$. The varying $c$…

General Relativity and Quantum Cosmology · Physics 2023-04-05 Rodrigo R. Cuzinatto , Rajendra P. Gupta , Pedro J. Pompeia

In this work we shall study the late-time dynamics of several $F(R)$ gravity models. By appropriately expressing the field equations in terms of the redshift and of a statefinder function, we shall solve numerically the field equations…

General Relativity and Quantum Cosmology · Physics 2022-09-07 V. K. Oikonomou , Ifigeneia Giannakoudi

In considering alternative higher-order gravity theories, one is liable to be motivated in pursuing models consistent and inspired by several candidates of a fundamental theory of quantum gravity. Indeed, motivations from string/M-theory…

General Relativity and Quantum Cosmology · Physics 2015-03-17 Nadiezhda Montelongo García , Tiberiu Harko , Francisco S. N. Lobo , José P. Mimoso

We use the correspondence between the $f(R)$ theory and an Einstein-scalar field system to study late-time dynamics of solutions of $f(R)$ theory. We discuss how reasonable assumptions on the potential of the scalar field lead to…

General Relativity and Quantum Cosmology · Physics 2008-10-21 Lucy Macnay

We review various modified gravities considered as gravitational alternative for dark energy. Specifically, we consider the versions of $f(R)$, $f(G)$ or $f(R,G)$ gravity, model with non-linear gravitational coupling or string-inspired…

High Energy Physics - Theory · Physics 2009-09-17 S. Nojiri , S. D. Odintsov

In this work, we present a method for numerically solving the Friedmann equations of modified $f(\mathcal{G})$ gravity in the presence of pressureless matter. This method enables us to predict the redshift behaviour of the Hubble expansion…

General Relativity and Quantum Cosmology · Physics 2024-11-08 Santosh V. Lohakare , Soumyadip Niyogi , B. Mishra

In this paper we study scalar perturbations of the metric for nonlinear $f(R)$ models. We consider the Universe at the late stage of its evolution and deep inside the cell of uniformity. We investigate the astrophysical approach in the case…

Cosmology and Nongalactic Astrophysics · Physics 2014-09-04 Maxim Eingorn , Jan Novák , Alexander Zhuk
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