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We have investigated some bouncing cosmological models in an isotropic and homogeneous space time with the F(R) theory of gravity. Two functional forms of F(R) have been investigated with a bouncing scale factor. The dynamical parameters…

General Relativity and Quantum Cosmology · Physics 2024-03-21 A. S. Agrawal , S. Mishra , S. K. Tripathy , B. Mishra

We argue that more cosmological solutions in massive gravity can be obtained if the metric tensor and the tensor $\Sigma_{\mu\nu}$ defined by St\"{u}ckelberg fields take the homogeneous and isotropic form. The standard cosmology with matter…

General Relativity and Quantum Cosmology · Physics 2015-06-05 Yungui Gong

We study cosmological braneworld models with a single timelike extra dimension. Such models admit the intriguing possibility that a contracting braneworld experiences a natural bounce without ever reaching a singular state. This feature…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Yuri Shtanov , Varun Sahni

We study the static cosmological solutions and their stability at background level in the framework of massive bigravity theory with Friedmann-Robertson-Walker (FRW) metrics. By the modification proposed in the cosmological equations…

General Relativity and Quantum Cosmology · Physics 2017-05-17 M. Mousavi , F. Darabi

The ghost-free theory of massive gravity has exact solutions where the effective stress energy generated by the graviton mass term is a cosmological constant for any isotropic metric. Since they are exact, these solutions mimic a…

High Energy Physics - Theory · Physics 2013-05-15 Mark Wyman , Wayne Hu , Pierre Gratia

In this study, we introduce an extension of the quasi-dilaton massive gravity theory and derive the field equations by varying the action with respect to the metric. This extension elucidates the dynamics of the system and demonstrates how…

General Relativity and Quantum Cosmology · Physics 2025-05-27 Sobhan Kazempour , Amin Rezaei Akbarieh , Sichun Sun , Chengye Yu

We study the dynamics of the homogeneous and isotropic cosmological background in the recently proposed ``quantum phenomenological gravitational dynamics'', characterised by logarithmic corrections to the Bekenstein entropy. We show that…

General Relativity and Quantum Cosmology · Physics 2023-07-21 Marco de Cesare , Giulia Gubitosi

Massive bigravity, a theoretically consistent modification of general relativity with an additional dynamical rank two tensor, successfully describes the observed accelerated expansion of the Universe without a cosmological constant. Recent…

Cosmology and Nongalactic Astrophysics · Physics 2015-08-12 Matthew Johnson , Alexandra Terrana

The present work deals with a FLRW cosmological model with spatial curvature and minimally coupled scalar field as the matter content. The curvature term behaves as a perfect fluid with the equation of state parameter w_K = -1/3 Using…

General Relativity and Quantum Cosmology · Physics 2024-07-09 Soumya Chakraborty , Sudip Mishra , Subenoy Chakraborty

We study the cosmic expansion history of massive bigravity with a viable matter coupling which treats both metrics on equal footing. We derive the Friedmann equation for the effective metric through which matter couples to the two metrics,…

Cosmology and Nongalactic Astrophysics · Physics 2015-01-13 Jonas Enander , Adam R. Solomon , Yashar Akrami , Edvard Mortsell

Massive bigravity models are interesting alternatives to standard cosmology. In most cases, however, these models have been studied for a simplified scenario in which both metrics take homogeneous and isotropic forms…

General Relativity and Quantum Cosmology · Physics 2015-11-18 Henrik Nersisyan , Yashar Akrami , Luca Amendola

We consider solutions to the Einstein-massless-scalar field system with a positive cosmological constant, arising from sufficiently regular, near-FLRW, initial data. We establish global existence in the future direction and derive their…

Analysis of PDEs · Mathematics 2022-03-23 Grigorios Fournodavlos

In this article, we explore the homogeneous and isotropic flat Friedmann-Robertson-Walker (FRW) model in Chameleon cosmology. By considering a non-minimal coupling between the scalar field and matter, we present a non-singular bouncing…

General Relativity and Quantum Cosmology · Physics 2022-12-06 Ashutosh Singh , Anirudh Pradhan

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

A bouncing scenario of a flat homogeneous and isotropic universe is explored by using the reconstruction technique for the power-law parametrization of the Hubble parameter in a modified gravity theory with higher-order curvature and trace…

General Relativity and Quantum Cosmology · Physics 2023-04-03 J. K. Singh , Harshna Balhara , Kazuharu Bamba , J. Jena

This paper is devoted to examining cosmological bouncing scenarios in the framework of the recently proposed symmetric teleparallel gravity (or $f(Q)$ gravity), where the non-metricity scalar $Q$ represents the gravitational interaction. We…

Cosmology and Nongalactic Astrophysics · Physics 2024-09-17 M. Koussour , N. Myrzakulov

By using the braneworld model, we investigate the time evolution of microscopic and macroscopic correlations in expanding universes. To describe the FLRW cosmologies in the holographic setup, we take into account a braneworld moving in the…

High Energy Physics - Theory · Physics 2025-12-05 Chanyong Park , Hanse Kim , Kyungchan Cho

We examine the dynamics of FLRW cosmologies in which the vacuum interacts with a perfect fluid through an energy exchange, focusing on the exploration of nonsingular configurations, including cyclic and bouncing models. We consider two…

General Relativity and Quantum Cosmology · Physics 2022-05-06 Marco Bruni , Rodrigo Maier , David Wands

We study cosmology in the bigravity formulation of the dRGT model where matter couples to both metrics. At linear order in perturbation theory two mass scales emerge: an hard one from the dRGT potential, and an environmental dependent one…

High Energy Physics - Theory · Physics 2015-04-22 Denis Comelli , Marco Crisostomi , Kazuya Koyama , Luigi Pilo , Gianmassimo Tasinato

Bouncing non-singular isotropic cosmological solutions are investigated in a simple model of scalar-tensor gravity. New families of such solutions are found and their properties are presented and analyzed using an effective potential as the…

General Relativity and Quantum Cosmology · Physics 2022-01-28 D. Polarski , A. A. Starobinsky , Y. Verbin
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