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Related papers: Bouncing Universe with exotic radiation

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In this paper, we model the bounce phase, stability, and the reconstruction of the universe by non-minimal kinetic coupling. In the process, we obtained importance information about the energy density and the matter pressure of the universe…

General Relativity and Quantum Cosmology · Physics 2026-02-10 Alireza Amani , A. S. Kubeka , E. Mahichi

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…

General Relativity and Quantum Cosmology · Physics 2018-07-04 J. K. Singh , Kazuharu Bamba , Ritika Nagpal , S. K. J. Pacif

In a braneworld description of our universe, we must allow for the possibility of having dynamical branes around the time of the big bang. Some properties of such domain walls in motion are discussed here, for example the ability of…

High Energy Physics - Theory · Physics 2011-03-10 Jean-Luc Lehners

We investigate classically non-singular bounces caused by dark energy. In the presence of positive spatial curvature, vacuum energy, either in the form of a cosmological constant or a scalar field potential, allows for an open set of…

High Energy Physics - Theory · Physics 2019-06-26 Sebastian F. Bramberger , Jean-Luc Lehners

We present the ${\cal E}$-boson star: A novel configuration of a boson star with an exotic matter nucleus; the exotic matter being described by a real massive scalar field with self-interaction term and kinetic term of the opposite sign.…

General Relativity and Quantum Cosmology · Physics 2023-04-05 Víctor Jaramillo , Erik Jiménez-Vázquez , Darío Núñez

In this paper we argue that modified Friedmann equations with a bounce solution can be derived from a modified dispersion relation by employing a thermodynamical description of general relativity on the apparent horizon.

General Relativity and Quantum Cosmology · Physics 2010-04-30 Yi Ling , Wei-Jia Li , Jian-Pin Wu

A bounce universe model with a scale-invariant and stable spectrum of primordial density perturbations was constructed using a consistent truncation of the D-brane dynamics from Type IIB string theory. A coupling was introduced between the…

General Relativity and Quantum Cosmology · Physics 2019-01-23 Yeuk-Kwan E. Cheung , Xue Song , Shuyi Li , Yunxuan Li , Yiqing Zhu

We propose a new scenario for the bouncing universe in a simple five-dimensional braneworld model in the framework of Einstein-Gauss-Bonnet gravity, which works even with ordinary matter on the brane. In this scenario, the so-called branch…

High Energy Physics - Theory · Physics 2013-02-15 Hideki Maeda

Cosmological bounces occur in many gravity theories. We define singularity scattering maps relating large scale geometries before and after the bounce (assuming no BKL oscillations) and encoding microscopic details of the theory. By…

General Relativity and Quantum Cosmology · Physics 2021-05-05 Bruno Le Floch , Philippe G. LeFloch , Gabriele Veneziano

The spectrum and amplitude of the stochastic background of relic gravitons produced in a bouncing universe is calculated. The matter content of the model consists of dust and radiation fluids, and the bounce occurs due to quantum…

General Relativity and Quantum Cosmology · Physics 2015-06-05 Dennis Bessada , Nelson Pinto-Neto , Beatriz B. Siffert , Oswaldo D. Miranda

Oscillating solutions to the effective equations of Loop Quantum Cosmology have been suggested for the role of an `eternal seed', providing a possible starting point for the emergent universe scenario. We investigate the stability of a…

High Energy Physics - Theory · Physics 2015-06-19 Audrey T. Mithani , Alexander Vilenkin

Despite its great successes in accounting for the current observations, the so called `standard' model of cosmology faces a number of fundamental unresolved questions. Paramount among these are those relating to the nature of the origin of…

General Relativity and Quantum Cosmology · Physics 2008-02-29 Martin Bojowald , Reza Tavakol

We study the dynamics of states perturbatively expanded about a harmonic system of loop quantum cosmology, exhibiting a bounce. In particular, the evolution equations for the first and second order moments of the system are analyzed. These…

General Relativity and Quantum Cosmology · Physics 2011-01-20 Martin Bojowald , David Mulryne , William Nelson , Reza Tavakol

The baryon-antibaryon asymmetry (excess of matter over antimatter in our Universe), indicated by observational data from the Cosmic Microwave Background anisotropies, predictions of primordial Nucleosynthesis, and the absence of intense…

General Relativity and Quantum Cosmology · Physics 2020-10-13 P. C. M. Delgado , M. B. Jesus , N. Pinto-Neto , T. Mourão , G. S. Vicente

We introduce a string-inspired model for a bouncing/cyclic universe, utilizing the scalar-tachyon coupling as well as contribution from curvature in a closed universe. The universe undergoes the locked inflation, tachyon matter dominated…

General Relativity and Quantum Cosmology · Physics 2014-01-22 Changhong Li , Lingfei Wang , Yeuk-Kwan E. Cheung

In this work, we have studied how incorporating viscous fluids leads to exact bounce cosmological solutions in general relativity (GR) framework. Specifically, we propose a novel parameterization of bulk viscosity coefficient of the form…

General Relativity and Quantum Cosmology · Physics 2024-07-23 Rajdeep Mazumdar , Mrinnoy M. Gohain , Kalyan Bhuyan

The present article discusses about the effect of a Lee-Wick partner infested radiation phase of the early universe. As Lee-Wick partners can contribute negative energy density so it is always possible that at some early phase of the…

High Energy Physics - Theory · Physics 2013-04-16 Kaushik Bhattacharya , Yi-Fu Cai , Suratna Das

We present several higher-dimensional spacetimes for which observers living on 3-branes experience an induced metric which bounces. The classes of examples include boundary branes on generalised S-brane backgrounds and probe branes in…

High Energy Physics - Theory · Physics 2009-11-10 C. P. Burgess , F. Quevedo , R. Rabadan , G. Tasinato , I. Zavala

Bouncing models have been proposed by many authors as a completion, or even as an alternative to inflation for the description of the very early and dense Universe. However, most bouncing models contain a contracting phase from a very large…

Cosmology and Nongalactic Astrophysics · Physics 2012-01-31 Rodrigo Maier , Stella Pereira , Nelson Pinto-Neto , Beatriz B. Siffert

We propose a set of equations as a simple model for non singular evolutions of a $10 + 1$ dimensional M theory universe. Our model uses ideas from Loop Quantum Cosmology and offers a solution to the important problem of singularity…

High Energy Physics - Theory · Physics 2020-02-25 Saroj Prasad Chhatoi , S. Kalyana Rama