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Related papers: Einstein-Gauss-Bonnet gravity: is it compatible wi…

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We study the inflationary phenomenology of a rescaled Einstein-Gauss-Bonnet gravity. In this framework, the gravitational constant of the Einstein-Hilbert term is rescaled due to effective terms active in the high curvature era. Basically,…

General Relativity and Quantum Cosmology · Physics 2025-03-25 V. K. Oikonomou , Ardit Gkioni , Iason Sdranis , Pyotr Tsyba , Olga Razina

In recent few years, the Gauss-Bonnet $f(\mathcal{G},\mathrm{\textit{T}})$ theory of gravity has fascinated considerable researchers owing to its coupling of trace of the stress-energy tensor $T$ with the Gauss-Bonnet term $\mathcal{G}$. In…

General Relativity and Quantum Cosmology · Physics 2023-04-14 Mushtaq Ahmad , M. Farasat Shamir , G. Mustafa

In standard general relativity the universe cannot be started with arbitrary initial conditions, because four of the ten components of the Einstein's field equations (EFE) are constraints on initial conditions. In the previous work it was…

General Relativity and Quantum Cosmology · Physics 2017-11-08 Tomonori Totani

Cosmological consequences of a string-motivated dark energy scenario featuring a scalar field coupled to the Gauss-Bonnet invariant are investigated. We study the evolution of the universe in such a model, identifying its key properties.…

Astrophysics · Physics 2008-11-26 Tomi Koivisto , David F. Mota

The free parameters of a flat accelerating model without dark energy are constrained by using Supernovae type Ia and observational H(z) data. Instead of the vacuum dominance, the present accelerating stage in this modified Einstein-de…

Cosmology and Nongalactic Astrophysics · Physics 2016-11-15 R. C. Santos , F. E. Silva , J. A. S. Lima

We study the holographic s+p model in both four dimensional (4D) and five dimensional (5D) Einstein-Gauss-Bonnet (EGB) gravity. We first show a phase diagram with the Gauss-Bonnet parameter fixed to a small value $\alpha=10^{-7}$ to choose…

High Energy Physics - Theory · Physics 2023-06-26 Xing-Kun Zhang , Zhang-Yu Nie , Hui Zeng , Qiyuan Pan

In this paper, we study the phase space of cosmological models in the context of Einstein-Gauss-Bonnet theory. More specifically, we consider a generalized dynamical system that encapsulates the main features of the theory and for the cases…

General Relativity and Quantum Cosmology · Physics 2020-07-15 N. Chatzarakis , V. K. Oikonomou

In the past few years, $f(Q)$ theories have drawn a lot of research attention in replacing Einstein's theory of gravity successfully. The current study examines the novel cosmological possibilities emerging from two specific classes of…

General Relativity and Quantum Cosmology · Physics 2023-05-31 M. Koussour , Avik De

The non-abelian Einstein-Born-Infeld-Dilaton theory, which rules the dynamics of tensor-scalar gravitation coupled to a $su(2)$-valued gauge field ruled by Born-Infeld lagrangian, is studied in a cosmological framework. The microscopic…

General Relativity and Quantum Cosmology · Physics 2011-07-19 A. Fuzfa , J. -M. Alimi

This study investigates the cosmological dynamics of an accelerating universe within the framework of teleparallel gravity using an exponential f(T) functional form. To obtain exact cosmological solutions, a hybrid scale factor is employed…

General Relativity and Quantum Cosmology · Physics 2026-05-27 Rajalakshmi Jena , Vishal M C , Sankarsan Tarai

An explicitly covariant formulation is presented of a modified DGP scenario proposed recently [1], to avoid the instability of the self-accelerating branch. It is based on the introduction of a bulk scalar field with appropriate non-minimal…

High Energy Physics - Theory · Physics 2008-11-26 Alexey S. Koshelev , Theodore N. Tomaras

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

The observed acceleration of the Universe can be explained by modifying general relativity. One such attempt is the nonlocal model of Deser and Woodard. Here we fix the background cosmology using results from the Planck satellite and…

Cosmology and Nongalactic Astrophysics · Physics 2014-09-05 Scott Dodelson , Sohyun Park

In this paper the focus is on inflationary dynamics in the context of Einstein Gauss-Bonnet gravitational theories. We investigate the implications of the slow-roll condition on the slow-roll indices and we investigate how the inflationary…

General Relativity and Quantum Cosmology · Physics 2018-09-26 S. D. Odintsov , V. K. Oikonomou

We explore cosmology with a bounce in Gauss-Bonnet gravity where the Gauss-Bonnet invariant couples to a dynamical scalar field. In particular, the potential and and Gauss-Bonnet coupling function of the scalar field are reconstructed so…

High Energy Physics - Theory · Physics 2015-06-23 Kazuharu Bamba , Andrey N. Makarenko , Alexandr N. Myagky , Sergei D. Odintsov

We deal with Einstein-Gauss-Bonnet model in dimension $D$ with a $\Lambda$-term. We obtain three stable cosmological solutions with exponential behavior (in time) of three scale factors corresponding to subspaces of dimensions…

General Relativity and Quantum Cosmology · Physics 2019-06-19 K. K. Ernazarov , V. D. Ivashchuk

Modifications of gravity generated by a multiplicative coupling of a scalar field to the electromagnetic Lagrangian lead to a breaking of Einstein equivalence principle (EEPB) as well as to variations of fundamental constants. In these…

Cosmology and Nongalactic Astrophysics · Physics 2021-11-01 R. F. L. Holanda , K. N. N. O. Barros

Einstein's theory of general relativity (GR) has been precisely tested on solar system scales, but extragalactic tests are still poorly performed. In this work, we use a newly compiled sample of galaxy-scale strong gravitational lenses to…

Cosmology and Nongalactic Astrophysics · Physics 2022-03-02 Jun-Jie Wei , Yun Chen , Shuo Cao , Xue-Feng Wu

A cosmological model with a specific form of the Hubble parameter is constructed in a flat homogeneous, and isotropic background in the framework of $f(R, T)$ gravity, where $R$ is the scalar curvature and $T$ is the trace of the…

General Relativity and Quantum Cosmology · Physics 2018-07-04 J. K. Singh , Kazuharu Bamba , Ritika Nagpal , S. K. J. Pacif

We explore the dynamics and evolution of the Universe at early and late times, focusing on both dark energy and extended gravity models and their astrophysical and cosmological consequences. Modified theories of gravity not only provide an…