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We study multidimensional cosmological models with a higher-dimensional product manifold, that consists of spherical and flat spaces, in the presence of a minimal free scalar field. Dynamical behaviour of the model is analyzed both in…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Baukh Victor

We investigated the cosmology in a higher-curvature gravity where the dimensionality of spacetime gives rise to only quantitative difference, contrary to Einstein gravity. We found exponential type solutions for flat isotropic and…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Y. Ezawa , H. Iwasaki , M. Ohmori , S. Ueda , N. Yamada , T. Yano

Homogeneous isotropic cosmological models with two torsion functions filled with scalar fields and usual gravitating matter are built and investigated in the framework of the Poincar\'e gauge theory of gravity. It is shown that by certain…

General Relativity and Quantum Cosmology · Physics 2008-11-26 A. V. Minkevich , A. S. Garkun , V. I. Kudin

In the last century, theoretical and experimental developments have established the General Relativity theory as the most successful theory for describing the gravitational phenomenon. On the other hand, in the last two decades, multiple…

General Relativity and Quantum Cosmology · Physics 2025-02-18 Raja Solanki

We review a few off-the-beaten-track ideas in cosmology. They solve a variety of fundamental problems; also they are fun. We start with a description of non-singular dilaton cosmology. In these scenarios gravity is modified so that the…

High Energy Physics - Phenomenology · Physics 2007-05-23 Robert H. Brandenberger , Joao Magueijo

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

We investigate the cosmology of a recently proposed deformation of Einstein gravity, emerging from quantum gravity heuristics. The theory is constructed to have de Sitter space as a vacuum solution, and thus to be relevant to the…

A class of Einstein-dilaton-axion models is found for which almost all flat expanding homogeneous and isotropic universes undergo recurrent periods of acceleration. We also extend recent results on eternally accelerating open universes.

High Energy Physics - Theory · Physics 2008-11-26 Julian Sonner , Paul K. Townsend

We construct a model of higher dimensional cosmology in which extra dimensions are frozen by virtue of the cubic-order Lovelock gravity throughout the cosmic history from inflation to the present with radiation and matter-dominated regimes…

General Relativity and Quantum Cosmology · Physics 2020-10-21 Hiroaki W. H. Tahara , Tsutomu Kobayashi , Jun'ichi Yokoyama

Within the theory of the ghost-free bigravity, we present the most general cosmological solution for which the physical metric is homogeneous and isotropic, while the second metric is inhomogeneous. The solution includes a matter source and…

High Energy Physics - Theory · Physics 2015-06-05 Mikhail S. Volkov

We consider the gravitational model with additional spatial dimensions and anisotropic pressure which is nonzero only in these dimensions. Cosmological solutions in this model include accelerated expansion of the Universe at late age of its…

General Relativity and Quantum Cosmology · Physics 2014-02-19 O. A. Grigorieva , G. S. Sharov

I briefly discuss the challenges presented by attempting to modify general relativity to obtain an explanation for the observed accelerated expansion of the universe. Foremost among these are the questions of theoretical consistency - the…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Mark Trodden

The current standard cosmological model is constructed within the framework of general relativity with a cosmological constant $\Lambda$, which is often associated with dark energy, and phenomenologically explains the accelerated cosmic…

General Relativity and Quantum Cosmology · Physics 2023-06-27 Jiamin Hou , Julian Bautista , Maria Berti , Carolina Cuesta-Lazaro , César Hernández-Aguayo , Tilman Tröster , Jinglan Zheng

This paper explores the Friedmann field equations within the framework of Lovelock gravity, a natural extension of Einstein's gravity, focusing on both flat and open universes. Utilizing an approach based on independent Riemann tensor…

General Relativity and Quantum Cosmology · Physics 2024-12-30 Aleksei Nikolaev

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

Recently it has been proposed that the Gauss-Bonnet coupling parameter of Lovelock gravity may suitably be rescaled in order to admit physically viable models of celestial phenomena such that higher curvature effects are active in standard…

General Relativity and Quantum Cosmology · Physics 2021-02-03 Sudan Hansraj , Ayan Banerjee , Lushen Moodly , M. K. Jasim

Solutions to flat space Friedmann-Robertson-Walker cosmologies in Brans-Dicke theory with a cosmological constant are investigated. The matter is modelled as a $\gamma$-law perfect fluid. The field equations are reduced from fourth order to…

General Relativity and Quantum Cosmology · Physics 2009-10-22 Shawn J. Kolitch

New nondiagonal $G_{2}$ inhomogeneous cosmological solutions are presented in a wide range of scalar-tensor theories with a stiff perfect fluid as a matter source. The solutions have no big-bang singularity or any other curvature…

General Relativity and Quantum Cosmology · Physics 2009-11-07 Stoytcho S. Yazadjiev

We review the topic of 4D Einstein-Gauss-Bonnet gravity, which has been the subject of considerable interest over the past two years. Our review begins with a general introduction to Lovelock's theorem, and the subject of Gauss-Bonnet terms…

General Relativity and Quantum Cosmology · Physics 2022-03-14 Pedro G. S. Fernandes , Pedro Carrilho , Timothy Clifton , David J. Mulryne

We investigate a class of cosmological solutions of Einstein's field equations in higher dimensions with a cosmological constant and an ideal fluid matter distribution as a source. We discuss the dynamical evolution of the universe subject…

General Relativity and Quantum Cosmology · Physics 2013-02-15 Ozgur Akarsu , Tekin Dereli