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We explore dynamics of cosmological models with bounce solutions evolving on a spatially flat Friedmann-Lemaitre-Robertson-Walker background. We consider cosmological models that contain the Hilbert-Einstein curvature term, the induced…

General Relativity and Quantum Cosmology · Physics 2016-12-08 Ekaterina O. Pozdeeva , Maria A. Skugoreva , Alexey V. Toporensky , Sergey Yu. Vernov

Motivated by conventional gauge theories, we consider a theory of gravity in which the Einstein-Hilbert action is replaced by a term that is quadratic in the Riemann tensor. We focus on cosmological solutions to the field equations in flat,…

General Relativity and Quantum Cosmology · Physics 2007-05-23 A. N. Lasenby , C. J. L. Doran , R. Heineke

This work is the extension of author`s research, where the modified theory of induced gravity (MTIG) is proposed. The theory describes two systems (stages): Einstein (ES) and "restructuring" (RS). We consider equations with quadratic…

General Physics · Physics 2019-11-22 Farkhat Zaripov

I construct an Einstein-Cartan ekpyrotic model (ECEM): a homogeneous, nearly Friedmann-Lema\^itre-Robertson-Walker (FLRW) background in Einstein-Cartan (EC) gravity whose spin-torsion sector, modeled phenomenologically as a Weyssenhoff…

General Relativity and Quantum Cosmology · Physics 2026-04-24 Jackson Stingley

We consider the problem of building inhomogeneous cosmological models in scalar-tensor theories of gravity. This starts by splitting the field equations of these theories into constraint and evolution equations, and then proceeds by…

General Relativity and Quantum Cosmology · Physics 2019-09-04 Jessie Durk , Timothy Clifton

One of the major obstacles to testing alternative theories of gravity with gravitational-wave data from merging binaries of compact objects is the formulation of their field equations, which is often mathematically ill-suited for time…

General Relativity and Quantum Cosmology · Physics 2022-11-11 Nicola Franchini , Miguel Bezares , Enrico Barausse , Luis Lehner

We construct a class of generalized non-local gravity (GNLG) model which is the modified theory of general relativity (GR) obtained by adding a term $m^{2n-2} R\Box^{-n}R$ to the Einstein-Hilbert action. Concretely, we not only study the…

General Relativity and Quantum Cosmology · Physics 2016-11-23 Xue Zhang , Ya-Bo Wu , Song Li , Yu-Chen Liu , Bo-Hai Chen , Yun-Tian Chai , Shuang Shu

This study investigates the modeling of anisotropic magnetized static neutron stars within the framework of five-dimensional Einstein-Gauss-Bonnet (5D EGB) gravity. While Einstein's gravity has traditionally been employed to examine neutron…

General Relativity and Quantum Cosmology · Physics 2025-08-21 Mohammad Mazhari

The Einstein-dilaton-Gauss-Bonnet (EdGB) theory is a modified theory of gravity which include a scalar field to couple with the higher order curvature terms. It has already been constrained with various observations include the…

General Relativity and Quantum Cosmology · Physics 2025-09-25 Jing Tan , Jian-dong Zhang , Hui-Min Fan , Jianwei Mei

We consider non-local Integral Kernel Theories of Gravity in a homogeneous and isotropic universe background as a possible scenario to drive the cosmic history. In particular, we investigate the cosmological properties of a gravitational…

General Relativity and Quantum Cosmology · Physics 2024-09-02 Salvatore Capozziello , Rocco D'Agostino , Orlando Luongo

We trace the origin of the cosmological constant problem to the assumption that Newton's constant $G$ sets the scale for cosmology. And then we show that once this assumption is relaxed, the very same cosmic acceleration which has served to…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Philip D. Mannheim

The recent observational data in cosmology seem to indicate that the universe is currently expanding in an accelerated way. An intriguing interpretation of these data is that they may just be signalling that Einstein's General Relativity is…

High Energy Physics - Theory · Physics 2018-05-18 Fulvio Sbisà

In this paper, we have explored the field equations of f(T, B) gravity as an extension of teleparallel gravity in an isotropic and homogeneous space time. In the basic formalism developed, the dynamical parameters are derived by…

General Relativity and Quantum Cosmology · Physics 2024-09-27 S. A. Kadam , Jackson Levi Said , B. Mishra

Modified gravity theories such as Einstein scalar Gauss Bonnet (EsGB) contain higher derivative terms in the spacetime curvature in their action, which results in modifications to the Hamiltonian and momentum constraints of the theory. In…

General Relativity and Quantum Cosmology · Physics 2023-12-01 Sam E. Brady , Llibert Aresté Saló , Katy Clough , Pau Figueras , Annamalai P. S

A D-dimensional gravitational model with Gauss-Bonnet term is considered. When ansatz with diagonal cosmological type metrics is adopted, we find solutions with exponential dependence of scale factors (with respect to "synchronous-like"…

General Relativity and Quantum Cosmology · Physics 2016-10-04 V. D. Ivashchuk , A. A. Kobtsev

In this study, we present an approach $ f(R, G) $ gravity incorporating power law in $ G $. To study the cosmic evolution of the universe given by the reconstruction of the Hubble parameter given by $ E(z) = \bigg(…

General Relativity and Quantum Cosmology · Physics 2024-09-30 Rita Rani , Shaily , G. K. Goswami , J. K. Singh

A scalar-tensor theory of gravity is considered wherein the gravitational coupling $G$ and the speed of light $c$ are admitted as space-time functions and combine to form the definition of the scalar field $\phi$. The varying $c$…

General Relativity and Quantum Cosmology · Physics 2023-04-05 Rodrigo R. Cuzinatto , Rajendra P. Gupta , Pedro J. Pompeia

The Nobel Prize winning confirmation in 1998 of the accelerated expansion of our Universe put into sharp focus the need of a consistent theoretical model to explain the origin of this acceleration. As a result over the past two decades…

General Relativity and Quantum Cosmology · Physics 2018-12-07 Sebastian Bahamonde , Christian G. Boehmer , Sante Carloni , Edmund J. Copeland , Wei Fang , Nicola Tamanini

Recently we have proposed models of topological field theory including gravity in Mod. Phys. Lett. A 31 (2016) no.37, 1650213 and Phys. Rev. D 96 (2017) no.2, 024009, in order to solve the problem of the cosmological constant. The…

High Energy Physics - Theory · Physics 2019-07-16 Taisaku Mori , Shin'ichi Nojiri

A generalized dynamical equation for the scale factor of the universe is proposed to describe the cosmological evolution, of which the $\Lambda$CDM model is a special case. It also provides a general example to show the equivalence of the…

Astrophysics · Physics 2009-11-11 J. Ren , X. H. Meng