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Related papers: Unimodular $f(G)$ gravity

200 papers

Mimetic gravity is analysed in the framework of some extensions of General Relativity, where a function of the Gauss-Bonnet invariant in four dimensions is considered. By assuming the so-called mimetic condition, the conformal degree of…

General Relativity and Quantum Cosmology · Physics 2018-05-22 Yi Zhong , Diego Saez-Chillon Gomez

We combine the unimodular gravity and mimetic gravity theories into a unified theoretical framework, which is proposed to provide a suggestive proposal for a framework that may assist in the discussion and solution search of the…

General Relativity and Quantum Cosmology · Physics 2016-05-25 S. Nojiri , S. D. Odintsov , V. K. Oikonomou

Here we analysed a particular type of $F(R)$ gravity, the so-called exponential gravity which includes an exponential function of the Ricci scalar in the action. Such term represents a correction to the usual Hilbert-Einstein action. By…

General Relativity and Quantum Cosmology · Physics 2018-01-17 Sergei D. Odintsov , Diego Saez-Chillon Gomez , German S. Sharov

Unimodular gravity is classically equivalent to General Relativity. This equivalence extends to actions which are functions of the curvature scalar. At the quantum level, the dynamics could differ. Most importantly, the cosmological…

General Relativity and Quantum Cosmology · Physics 2015-05-20 Astrid Eichhorn

In this paper, we have considered flat Friedmann-Lema\^{i}tre-Robertson-Walker metric in the framework of perfect fluid models and modified $f(G)$ gravity (where $G$ is the Gauss Bonnet invariant). Particularly, we have considered…

General Relativity and Quantum Cosmology · Physics 2017-08-08 Kazuharu Bamba , M. Ilyas , M. Z. Bhatti , Z. Yousaf

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

We propose the unimodular-mimetic $F(R)$ gravity theory, to resolve cosmological constant problem and dark matter problem in a unified geometric manner. We demonstrate that such a theory naturally admits accelerating universe evolution.…

General Relativity and Quantum Cosmology · Physics 2016-06-29 S. D. Odintsov , V. K. Oikonomou

We consider the cosmological implications of a four-dimensional extension of the Gauss-Bonnet $f(G)$ gravity, where $G$ is the Gauss-Bonnet topological invariant, in which the Einstein-Hilbert action is replaced by an arbitrary function…

General Relativity and Quantum Cosmology · Physics 2025-06-23 Ratul Mandal , Himanshu Chaudhary , Tiberiu Harko , Ujjal Debnath , G. Mustafa

Classically, unimodular gravity is known to be equivalent to General Relativity (GR), except for the fact that the effective cosmological constant $\Lambda$ has the status of an integration constant. Here, we explore various formulations of…

High Energy Physics - Theory · Physics 2014-11-18 Bartomeu Fiol , Jaume Garriga

We review how we can construct the gravity models which reproduces the arbitrary development of the universe. We consider the reconstruction in the Einstein gravity coupled with generalized perfect fluid, scalar-Einstein gravity,…

High Energy Physics - Theory · Physics 2010-04-28 Shin'ichi Nojiri

The treatment of 1 + 3 covariant perturbation in a multifluid cosmology with the consideration of f (G) gravity, G being the Gauss-Bonnet term, is done in the present paper. We define a set of covariant and gauge-invariant variables to…

General Relativity and Quantum Cosmology · Physics 2023-02-22 Albert Munyeshyaka , Abraham Ayirwanda , Fidele Twagirayezu , Joseph Ntahompagaze

The aim of this paper is to introduce a new modified gravity theory named as $f(\mathcal{G},T)$ gravity ($\mathcal{G}$ and $T$ are the Gauss-Bonnet invariant and trace of the energy-momentum tensor, respectively) and investigate energy…

General Relativity and Quantum Cosmology · Physics 2016-12-21 M. Sharif , Ayesha Ikram

Classical generalization of general relativity is considered as gravitational alternative for unified description of the early-time inflation with late-time cosmic acceleration. The structure and cosmological properties of number of…

General Relativity and Quantum Cosmology · Physics 2011-07-26 Shin'ichi Nojiri , Sergei D. Odintsov

We construct models with the Gauss-Bonnet term multiplied to a function of the scalar field leading to inflationary scenario. The consideration is related with the slow-roll approximation. The cosmological attractor approach gives the…

General Relativity and Quantum Cosmology · Physics 2020-07-29 E. O. Pozdeeva

The traditional presentation of Unimodular Gravity (UG) consists on indicating that it is an alternative theory of gravity that restricts the generic diffeomorphism invariance of General Relativity. In particular, as often encountered in…

General Relativity and Quantum Cosmology · Physics 2023-11-08 Gabriel R. Bengochea , Gabriel Leon , Alejandro Perez , Daniel Sudarsky

We examine the cosmological dynamics of Einstein-Gauss-Bonnet gravity models in a four-dimensional spatially flat FLRW metric. These models are described by $f\left( R,\mathcal{G}\right) =f\left( R+\mu \mathcal{G}\right) $ theory of…

General Relativity and Quantum Cosmology · Physics 2025-12-10 Nikolaos Dimakis , Alex Giacomini , Genly Leon , Andronikos Paliathanasis , Ekaterina Pozdeeva , Sergey Vernov

It is well known that classical Unimodular Gravity (UG) is equivalent to General Relativity, but is not clear the equivalence at the quantum level. Here we exhibit, in the UG framework, the Quantum Cosmology (QC) for a…

General Relativity and Quantum Cosmology · Physics 2022-08-31 J. A. Astorga-Moreno , Miguel A. García-Aspeitia , E. A. Mena-Barboza

Motivated by the dark energy issue, a minisuperspace approach to the stability for modified gravitational models in a four dimensional cosmological setting are investigated. Specifically, after revisiting the $f(R)$ case, $R$ being the…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Guido Cognola , Monica Gastaldi , Sergio Zerbini

In this work we review the issue of imposing the conservation of the energy-momentum tensor as a necessary condition to recover the equivalence between the unimodular gravity and General Relativity (GR) equipped with a cosmological…

General Relativity and Quantum Cosmology · Physics 2022-06-29 Júlio C. Fabris , Marcelo H. Alvarenga , Mahamadou Hamani-Daouda , Hermano Velten

This paper is devoted to investigate the recently introduced $f(\mathcal{G},\textit{T})$ theory of gravity, where $\mathcal{G}$ is the Gauss-Bonnet term, and ${\textit{T}}$ is the trace of the energy-momentum tensor. For this purpose,…

General Physics · Physics 2017-12-13 M. Farasat Shamir