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We investigate the possible occurrence of a positive cosmic acceleration in a spatially averaged, expanding, unbound Lemaitre-Tolman-Bondi cosmology. By studying an approximation in which the contribution of three-curvature dominates over…

Astrophysics · Physics 2009-11-11 Aseem Paranjape , T. P. Singh

This paper analyzes the possibility of bouncing and non-bouncing universes in the framework of four-dimensional Einstein-Gauss-Bonnet (4D-EGB) gravity, corresponding respectively to negative and positive coupling constants $\lambda$ of the…

Cosmology and Nongalactic Astrophysics · Physics 2024-06-11 H. Khodabakhshi , M. Farhang , H. Lü

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

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 study accelerating cosmological solutions of a general class of non-linear gravities which depend on Gauss-Bonnet and other higher derivative invariants. To achieve this goal a local formulation with auxiliary scalars for arbitrary…

High Energy Physics - Theory · Physics 2009-01-16 Salvatore Capozziello , Emilio Elizalde , Shin'ichi Nojiri , Sergei D. Odintsov

We investigate the regularized four-dimensional Einstein-Gauss-Bonnet ($4D$ EGB) gravity with a non-minimal scalar coupling function, which is an extension of the regularized $4D$ EGB theory. By introducing non-minimal coupling to the…

General Relativity and Quantum Cosmology · Physics 2023-03-23 Bilguun Bayarsaikhan , Sunly Khimphun , Phearun Rithy , Gansukh Tumurtushaa

We discuss a model which gives rise to cosmic self-acceleration due to modified gravity. Improvements introduced by this approach are the following: In the coordinate system commonly used, the metric does not grow in the bulk, and no…

High Energy Physics - Theory · Physics 2007-05-23 Gregory Gabadadze

We explore some cosmological features of the newly suggested 4D Gauss-Bonnet gravity through two different models assuming a varying cosmological constant. Observational constraints, such as the cosmic transit and the flat curvature, have…

General Relativity and Quantum Cosmology · Physics 2023-03-15 Nasr Ahmed , Ajab A. Alfreedi , Alaa A. Alzulaibani

A D-dimensional gravitational model with Gauss-Bonnet and cosmological term is considered. When ansatz with diagonal cosmological metrics is adopted, we overview recent solutions for zero cosmological term and find new examples of solutions…

General Relativity and Quantum Cosmology · Physics 2016-03-16 A. A. Kobtsev , V. D. Ivashchuk , K. K. Ernazarov

The modified F(R)-scalar-Gauss-Bonnet gravity is proposed as dark energy model. The reconstruction program for such theory is developed. It is explicitly demonstrated that the known classical universe expansion history (deceleration epoch,…

High Energy Physics - Theory · Physics 2008-11-26 Shin'ichi Nojiri , Sergei D. Odintsov , Petr V. Tretyakov

It is shown that Einstein gravity in four dimensions with small cosmological constant and small extra dimensions can be obtained by spontaneous compactification of Lovelock gravity in vacuum. Assuming that the extra dimensions are compact…

High Energy Physics - Theory · Physics 2009-09-09 Fabrizio Canfora , Alex Giacomini , Ricardo Troncoso , Steven Willison

We study the late-time evolution of the Universe within the f(R,G) gravity framework, where R is the Ricci scalar and G is the Gauss-Bonnet term. To make the model tractable, we propose a parametrization scheme and determine its parameters…

General Relativity and Quantum Cosmology · Physics 2026-05-12 Santosh V. Lohakare , B. Mishra , S. K. Maurya

In a very recent paper [1], we have proposed a novel $4$-dimensional gravitational theory with two dynamical degrees of freedom, which serves as a consistent realization of $D\to4$ Einstein-Gauss-Bonnet gravity with the rescaled…

General Relativity and Quantum Cosmology · Physics 2021-04-29 Katsuki Aoki , Mohammad Ali Gorji , Shinji Mukohyama

A general analysis of the induced brane dynamics is performed when the intrinsic curvature term is included in the action. Such a term is known to cause dramatic changes and is generically induced by quantum corrections coming from the bulk…

High Energy Physics - Theory · Physics 2010-05-28 Georgios Kofinas

A new degravitation mechanism within the framework of scalar tensor gravity is postulated and included by prescription. The mechanism eliminates all constant contributions from the potential to the Friedmann equation, leaving only the…

Cosmology and Nongalactic Astrophysics · Physics 2025-01-13 Øyvind Christiansen , Farbod Hassani , David F. Mota

The $(2k)$-th Gauss-Bonnet curvature is a generalization to higher dimensions of the $(2k)$-dimensional Gauss-Bonnet integrand, it coincides with the usual scalar curvature for $k=1$. The Gauss-Bonnet curvatures are used in theoretical…

Differential Geometry · Mathematics 2008-12-19 Mohammed Larbi Labbi

A solution of the (4+n)-dimensional vacuum Einstein equations is found for which spacetime is compactified on a compact hyperbolic manifold of time-varying volume to a flat four-dimensional FLRW cosmology undergoing accelerated expansion in…

High Energy Physics - Theory · Physics 2008-11-26 Paul K. Townsend , Mattias N. R. Wohlfarth

The Regge-Teitelboim formulation of gravity, which utilizes dynamical embeddings in a background space, effectively introduces source terms in the standard Einstein equations that are not attributable to the energy-momentum tensor. We show…

General Relativity and Quantum Cosmology · Physics 2022-08-31 S. Fabi , A. Stern , Chuang Xu

We discuss the possibility of obtaining the present acceleration of the universe via f(R) gravity theories which recently attracted much attention. It is known that f(R) theories generally have room for this. In this work we stress that the…

High Energy Physics - Theory · Physics 2008-11-26 Tonguç Rador

It is shown that a localized four-dimensional Einstein term, induced by quantum corrections, modifies significantly the law of gravity in a Randall-Sundrum brane world. In particular, the short-distance behavior of gravity changes from…

High Energy Physics - Theory · Physics 2010-02-03 E. Kiritsis , N. Tetradis , T. N. Tomaras
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