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相关论文: Bouncing cosmology in the limiting curvature theor…

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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…

广义相对论与量子宇宙学 · 物理学 2023-04-03 J. K. Singh , Harshna Balhara , Kazuharu Bamba , J. Jena

In the framework of massive gravity with a de Sitter reference metric, we study homogeneous and isotropic solutions with positive spatial curvature. Remarkably, we find that bounces can occur when cosmological matter satisfies the strong…

高能物理 - 理论 · 物理学 2015-06-16 David Langlois , Atsushi Naruko

Modeling of matter bounce in $f(R,T)$ gravity has been presented with no violation of the null energy condition. Only a closed universe with negative pressure is allowed in good agreement with some recent observations which favor a universe…

广义相对论与量子宇宙学 · 物理学 2022-06-22 Vinod Kumar Bhardwaj , Anirudh Pradhan , Nasr Ahmed , A. A. Shaker

We investigate a bounce realization in the framework of higher order curvature in $ f(R,T) $ modified theory of gravity. We perform a detailed analysis of the cosmological parameters to explain the contraction phase, the bounce phase, and…

广义相对论与量子宇宙学 · 物理学 2023-07-19 J. K. Singh , Shaily , Akanksha Singh , Aroonkumar Beesham , Hamid Shabani

A matter bouncing entropy-corrected cosmological model has been suggested. The model allows only positive curvature with negative pressure and no violation of the null energy condition. The result obtained in this paper is supported by some…

广义相对论与量子宇宙学 · 物理学 2022-10-12 Nasr Ahmed , Tarek M. Kamel , Mohamed I Nouh

It is generically believed that higher-order curvature corrections to the Einstein-Hilbert action might cure the curvature singularities that plague general relativity. Here we consider Einstein-scalar-Gauss-Bonnet gravity, the only…

广义相对论与量子宇宙学 · 物理学 2017-12-27 Laura Sberna , Paolo Pani

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…

广义相对论与量子宇宙学 · 物理学 2022-01-28 D. Polarski , A. A. Starobinsky , Y. Verbin

We find a class of solutions for a homogeneous and isotropic universe in which the initially expanding universe stops expanding, experiences contraction, and then expands again (the "bounce"), in the framework of Einstein gravity with a…

广义相对论与量子宇宙学 · 物理学 2019-06-26 Hiroki Matsui , Fuminobu Takahashi , Takahiro Terada

A cosmological model with a specific form of the Hubble parameter is constructed in a flat homogeneous, and isotropic background in the framework of $f(R, T)$ gravity, where $R$ is the scalar curvature and $T$ is the trace of the…

广义相对论与量子宇宙学 · 物理学 2018-07-04 J. K. Singh , Kazuharu Bamba , Ritika Nagpal , S. K. J. Pacif

A theory of gravitation is constructed in which all homogeneous and isotropic solutions are nonsingular, and in which all curvature invariants are bounded. All solutions for which curvature invariants approach their limiting values approach…

广义相对论与量子宇宙学 · 物理学 2009-10-22 R. Brandenberger , V. Mukhanov , A. Sornborger

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…

广义相对论与量子宇宙学 · 物理学 2016-12-08 Ekaterina O. Pozdeeva , Maria A. Skugoreva , Alexey V. Toporensky , Sergey Yu. Vernov

In Loop Quantum Gravity mathematically rigorous models of full quantum gravity were proposed. In this paper we study a cosmological sector of one of the models describing quantum gravity with positive cosmological constant coupled to…

广义相对论与量子宇宙学 · 物理学 2022-11-09 Marcin Kisielowski

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…

天体物理学 · 物理学 2009-11-11 Damien A. Easson , Frederic P. Schuller , Mark Trodden , Mattias N. R. Wohlfarth

A companion paper provides a proposal for cosmic singularity resolution based upon general features of a bouncing unitary cosmological model in the mini-superspace approximation. This paper analyses novel phenomenology that can be…

广义相对论与量子宇宙学 · 物理学 2018-12-17 Sean Gryb , Karim P. Y. Thébault

We consider general curvature-invariant modifications of the Einstein-Hilbert action that become important only in regions of extremely low space-time curvature. We investigate the far future evolution of the universe in such models,…

The big bang singularity could be understood as a breakdown of Einstein's General Relativity at very high energies. Adopting this viewpoint, other theories, that implement Einstein Cosmology at high energies, might solve the problem of the…

广义相对论与量子宇宙学 · 物理学 2015-06-15 Jaume Amorós , Jaume de Haro , Sergei D. Odintsov

We analyze the early-time isotropic cosmology in the so-called energy-momentum-squared gravity (EMSG). In this theory, a $T_{\mu\nu}T^{\mu\nu}$ term is added to the Einstein-Hilbert action, which has been shown to replace the initial…

广义相对论与量子宇宙学 · 物理学 2020-03-09 Ahmed H. Barbar , Adel M. Awad , Mohammad T. AlFiky

In a homogeneous and isotropic universe with non-zero spatial curvature we consider the effects of gravitational particle production in the dynamics of the universe. We show that the dynamics of the universe in such a background is…

广义相对论与量子宇宙学 · 物理学 2017-05-31 Andronikos Paliathanasis , John D. Barrow , Supriya Pan

We offer a new proposal for cosmic singularity resolution based upon a quantum cosmology with a unitary bounce. This proposal is illustrated via a novel quantization of a mini-superspace model in which there can be superpositions of the…

广义相对论与量子宇宙学 · 物理学 2018-12-17 Sean Gryb , Karim P. Y. Thébault

We propose a class of theories that can limit scalars constructed from the extrinsic curvature. Applied to cosmology, this framework allows us to control not only the Hubble parameter but also anisotropies without the problem of…

广义相对论与量子宇宙学 · 物理学 2020-10-06 Yuki Sakakihara , Daisuke Yoshida , Kazufumi Takahashi , Jerome Quintin
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