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Related papers: Emergent Universe Scenario in the Einstein-Gauss-B…

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This paper is devoted to study the stability/instability of the expansionfree self gravitating source in the framework of Einstein Gauss-Bonnet gravity. The source has been taken as Tolman-Bondi model which is homogenous in nature. The…

General Relativity and Quantum Cosmology · Physics 2015-04-22 G. Abbas , S. Sarwar

We provide a realisation of a singularity-free inflationary universe in the form of a simple cosmological model dominated at early times by a single minimally coupled scalar field with a physically based potential. The universe starts…

General Relativity and Quantum Cosmology · Physics 2008-11-26 George F. R. Ellis , Jeff Murugan , Christos G. Tsagas

We present a class of graviton-dilaton models which leads to a singularity free evolution of the universe. We study the evolution of a homogeneous isotropic universe. We follow an approach which enables us to analyse the evolution and…

High Energy Physics - Theory · Physics 2011-09-09 S. Kalyana Rama

We consider the theory obtained by adding to the usual string frame dilaton gravity action specially constructed higher derivative terms motivated by the limited curvature construction of [MukhanovET1992a] and determine the spatially…

High Energy Physics - Theory · Physics 2009-10-31 Damien A. Easson , Robert H. Brandenberger

We consider a gravitational theory that contains the Einstein term, a scalar field and the quadratic Gauss-Bonnet term. We focus on the early-universe dynamics, and demonstrate that the Ricci scalar does not affect the cosmological…

High Energy Physics - Theory · Physics 2015-09-30 Panagiota Kanti

In this Letter we present a general covariant modified theory of gravity in $D\!=\!4$ space-time dimensions which propagates only the massless graviton and bypasses the Lovelock's theorem. The theory we present is formulated in $D\!>\!4$…

General Relativity and Quantum Cosmology · Physics 2020-03-02 Dražen Glavan , Chunshan Lin

We consider a non singular origin for the Universe starting from an Einstein static Universe, the so called "emergent universe" scenario, in the framework of a theory which uses two volume elements $\sqrt{-{g}}d^{4}x$ and $\Phi d^{4}x$,…

General Relativity and Quantum Cosmology · Physics 2015-05-27 E. I. Guendelman

The possibility of evading Lovelock's theorem at $d=4$, via a singular redefinition of the dimensionless coupling of the Gauss-Bonnet term, has been extensively discussed in the cosmological context. The term is added as a quadratic…

High Energy Physics - Theory · Physics 2022-05-10 Claudio Corianò , Mario Cretì , Stefano Lionetti , Matteo Maria Maglio , Riccardo Tommasi

In the Emergent scenario, the Universe should evolve from a non-singular state replacing the typical singularity of General Relativity, for any initial condition. For the scalar field model in [1] we show that only a set of measure zero of…

General Relativity and Quantum Cosmology · Physics 2024-08-13 Molly Burkmar , Marco Bruni

De Sitter solutions play an important role in cosmology because the knowledge of unstable de Sitter solutions can be useful to describe inflation, whereas stable de Sitter solutions are often used in models of late-time acceleration of the…

General Relativity and Quantum Cosmology · Physics 2021-05-18 Sergey Vernov , Ekaterina Pozdeeva

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 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

By presenting a relation between average energy of the ensemble of probe photons and energy density of the Universe, in the context of {\it gravity's rainbow} or {\it doubly general relativity} scenario, we introduce a rainbow FRW Universe…

General Relativity and Quantum Cosmology · Physics 2015-12-15 M. Khodadi , Y. Heydarzade , K. Nozari , F. Darabi

We consider a non-standard generalized model of gravity coupled to a neutral scalar "inflaton" as well as to the fields of the electroweak bosonic sector. The essential new ingredient is employing two alternative non-Riemannian space-time…

General Relativity and Quantum Cosmology · Physics 2017-09-18 Eduardo Guendelman , Emil Nissimov , Svetlana Pacheva

We perform a semi-classical analysis of the Emergent Universe scenario for inflation. Fixing the background, and taking the inflaton to be homogenous, we cast the inflaton's evolution as a one-dimensional quantum mechanics problem. We find…

High Energy Physics - Theory · Physics 2013-11-20 Anthony Aguirre , John Kehayias

We consider cosmological dynamics in fourth order gravity with both $f(R)$ and $\Phi(\mathcal {G})$ correction to the Einstein gravity ($\mathcal{G}$ is the Gauss-Bonnet term). The particular case for which both terms are equally important…

General Relativity and Quantum Cosmology · Physics 2012-05-09 Mikhail M. Ivanov , Alexey V. Toporensky

We investigate axial quasi-normal modes of realistic neutron stars in Einstein-Gauss-Bonnet-dilaton gravity. We consider 8 realistic equations of state containing nuclear, hyperonic, and hybrid matter. We focus on the fundamental curvature…

General Relativity and Quantum Cosmology · Physics 2016-02-03 Jose Luis Blázquez-Salcedo , Luis Manuel González-Romero , Jutta Kunz , Sindy Mojica , Francisco Navarro-Lérida

We present the $d+1$ formulation of Einstein-scalar-Gauss-Bonnet (ESGB) theories in dimension $D=d+1$ and for arbitrary (spacelike or timelike) slicings. We first build an action which generalizes those of Gibbons-Hawking-York and Myers to…

General Relativity and Quantum Cosmology · Physics 2020-07-01 Félix-Louis Julié , Emanuele Berti

We show that in Gauss-Bonnet gravity with negative Gauss-Bonnet coefficient and without a cosmological constant, one can explain the acceleration of the expanding Universe. We first introduce a solution of the Gauss-Bonnet gravity with…

High Energy Physics - Theory · Physics 2009-11-10 M. H. Dehghani

Within the framework of Einstein-Gauss-Bonnet theory in five-dimensional spacetime ($5D$ EGB), we derive the hydrostatic equilibrium equations and solve them numerically to obtain neutron stars for both isotropic and anisotropic…

General Relativity and Quantum Cosmology · Physics 2024-10-15 Juan M. Z. Pretel , Ayan Banerjee , Anirudh Pradhan