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Related papers: Robust Non-Singular Bouncing Cosmology from Regula…

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We explore the features of a thick braneworld model in five dimensions governed by a Einstein-Gauss-Bonnet gravity with a non-minimal coupling to a dynamical scalar field. We consider two possible scalar-GB coupling function $\chi(\phi)$,…

General Relativity and Quantum Cosmology · Physics 2025-09-01 José Euclides G. Silva , Leandro A. Lessa , Roberto V. Maluf

We study stability of singularity-free cosmological solutions with positive cosmological constant based on projectable Ho\v{r}ava-Lifshitz (HL) theory. In HL theory, the isotropic and homogeneous cosmological solutions with bounce can be…

General Relativity and Quantum Cosmology · Physics 2017-03-08 Yosuke Misonoh , Mitsuhiro Fukushima , Shoichiro Miyashita

By quantizing the background as well as the perturbations in a simple one fluid cosmological model, we show that there exists an ambiguity in the choice of relevant variables, potentially leading to incompatible observational physical…

General Relativity and Quantum Cosmology · Physics 2022-03-09 Jaime de Cabo Martin

Spatially homogeneous cosmological models reduce to Hamiltonian systems in a low dimensional Minkowskian space moving on the total energy shell $H=0$. Close to the initial singularity some models (those of Bianchi type VIII and IX) can be…

General Relativity and Quantum Cosmology · Physics 2015-06-25 R. Graham

In dynamical system describing evolution of universe with the flat Friedmann-Robertson-Walker symmetry filled with barotropic dust matter and non-minimally coupled scalar field with a constant potential function an invariant manifold of the…

Cosmology and Nongalactic Astrophysics · Physics 2017-03-08 Orest Hrycyna

In this work, we analyzed the improved Deser-Woodard non-local gravity over the background of five different bouncing cosmologies, whose premise is avoid the initial singular state of the universe. We developed the numerical solution for…

General Relativity and Quantum Cosmology · Physics 2022-06-01 D. Jackson , R. Bufalo

Dynamical systems methods are used to investigate a cosmological model with non-minimally coupled scalar field and asymptotically quadratic potential function. We found that for values of the non-minimal coupling constant parameter…

General Relativity and Quantum Cosmology · Physics 2021-07-15 Orest Hrycyna

The Asymptotically Safe Gravity provides a framework for the description of gravity from the trans-Planckian regime to cosmological scales. According to this scenario, the cosmological constant and Newton's coupling are functions of the…

General Relativity and Quantum Cosmology · Physics 2018-03-14 Alfio Bonanno , Gabriele Gionti , Alessia Platania

This is the first paper in a series aimed to implement boundary conditions consistent with the constraints' propagation in 3D numerical relativity. Here we consider spherically symmetric black hole spacetimes in vacuum or with a minimally…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Gioel Calabrese , Luis Lehner , Manuel Tiglio

We investigate a particular type of classical nonsingular bouncing cosmology, which results from general relativity if we allow for degenerate metrics. The simplest model has a matter content with a constant equation-of-state parameter and…

General Relativity and Quantum Cosmology · Physics 2019-10-23 F. R. Klinkhamer , Z. L. Wang

Regular bouncing solutions in the framework of a scalar-tensor gravity model were found in a recent work. We reconsider the problem in the Einstein frame (EF) in the present work. Singularities arising at the limit of physical viability of…

General Relativity and Quantum Cosmology · Physics 2015-10-21 B. Boisseau , H. Giacomini , D. Polarski

We present a model of non-relativistic gravitational theory which is power-counting renormalizable in 3+1 dimensional spacetime. When applied to cosmology, the relativity-violation terms lead to a dark radiation component, which can give…

High Energy Physics - Theory · Physics 2009-11-13 Yi-Fu Cai , Emmanuel N. Saridakis

This paper is the second part of a trilogy dedicated to the following problem: given spherically symmetric characteristic initial data for the Einstein-Maxwell-scalar field system with a cosmological constant $\Lambda$, with the data on the…

General Relativity and Quantum Cosmology · Physics 2015-09-02 João L. Costa , Pedro M. Girão , José Natário , Jorge Drumond Silva

We consider a novel Bounce Universe model constructed within the framework of Horndeski gravity. We have analyzed the bispectrum of primordial scalar perturbations and evaluated the corresponding non-Gaussianities for this specific model.…

High Energy Physics - Theory · Physics 2025-08-26 Y. Ageeva , M. Kotenko , P. Petrov

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

We explore dynamics of cosmological models with a nonminimally coupled scalar field evolving on a spatially flat Friedmann-Lemaitre-Robertson-Walker background. We consider cosmological models including the Hilbert-Einstein curvature term…

General Relativity and Quantum Cosmology · Physics 2014-10-01 Maria A. Skugoreva , Alexey V. Toporensky , Sergey Yu. Vernov

Nonlinear electrodynamics, which acts as a source of gravity Einstein field equations, leads to emergent cosmology, an alternative solution which can avoid Big Bang singularity. In this paper, we explore the emerging universe in models of…

General Relativity and Quantum Cosmology · Physics 2023-01-25 Payel Sarkar , Prasanta Kumar Das

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…

General Relativity and Quantum Cosmology · Physics 2018-12-17 Sean Gryb , Karim P. Y. Thébault

This article deals with a nonrelativistic cosmological model based on Galilean covariance, formulated within a five-dimensional Galilean manifold. Within this framework, we construct an isotropic and homogeneous metric analogous to the…

General Relativity and Quantum Cosmology · Physics 2025-11-17 R. G. G. Amorim , A. F. Santos , K. V. S. Araújo , S. C. Ulhoa

The main objective of this manuscript is to investigate the bouncing cosmology in the background of $f(\mathcal{Q})$ gravity, where $\mathcal{Q}$ defines the non-metricity. For this purpose, we use the reconstruction approach and consider a…

General Relativity and Quantum Cosmology · Physics 2024-04-02 M. Sharif , M. Zeeshan Gul , Nusrat Fatima
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