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Related papers: Emergent scenario and different anisotropic models

200 papers

The evolution of a class of inhomogeneous spherically symmetric universe models possessing a varying cosmological term and a material fluid, with an adiabatic index either constant or not, is studied.

General Relativity and Quantum Cosmology · Physics 2015-06-25 Luis P. Chimento , Diego Pavon

We consider alternative inflationary cosmologies in massive gravity with degenerate reference metrics and study the feasibilities of the emergent universe scenario, bouncing and cyclic universes. We focus on the construction of the Einstein…

General Relativity and Quantum Cosmology · Physics 2019-05-28 Shou-Long Li , H. Lü , Hao Wei , Puxun Wu , Hongwei Yu

We consider an evolution of anisotropic cosmological model on the example of the Bianchi type I homogeneous universe. It is filled by the mixture of matter and dark energy with an arbitrary barotropic equation of state (EoS). The general…

General Relativity and Quantum Cosmology · Physics 2023-06-14 S L Parnovsky

So far all known singularity-free cosmological models are cylindrically symmetric. Here we present a new family of spherically symmetric non-singular models filled with imperfect fluid and radial heat flow, and satisfying the weak and…

General Relativity and Quantum Cosmology · Physics 2009-10-30 Naresh Dadhich

An occurrence of an oscillating Universe is showed using an inhomogeneous equation of state for dark energy fluid. The Hubble parameter described presents a periodic behavior such that early and late time acceleration are unified under the…

High Energy Physics - Theory · Physics 2014-11-18 Diego Sáez-Gómez

We study the emergent scenario, which is proposed to avoid the big bang singularity, in the Einstein-Cartan (EC) theory with a positive cosmological constant and a perfect fluid by analyzing the existence and stability of the Einstein…

General Relativity and Quantum Cosmology · Physics 2015-10-19 Qihong Huang , Puxun Wu , Hongwei Yu

To seek for a singularity free model universe from a perfect fluid scalar-metric cosmology, we work in the "\emph{Emergent Cosmology}" (EC) paradigm which is a non-singular alternative for cosmological inflation. By using two methods…

General Relativity and Quantum Cosmology · Physics 2018-06-26 Mohsen Khodadi , Kourosh Nozari

In the present work, we study the dynamical evolution of an homogeneous and anisotropic KS cosmological model, considering general relativity as the gravitational theory, such that there are three different perfect fluids in the matter…

General Relativity and Quantum Cosmology · Physics 2022-06-15 G. Oliveira-Neto , D. L. Canedo , G. A. Monerat

We study the evolution of LTB Universe models possessing a varying cosmological term and a material fluid.

General Relativity and Quantum Cosmology · Physics 2012-08-17 Luis P. Chimento , Diego Pavón

We explore the possibility of emergent cosmology using the effective potential formalism. We discover new models of emergent cosmology which satisfy the constraints posed by the cosmic microwave background (CMB). We demonstrate that, within…

Cosmology and Nongalactic Astrophysics · Physics 2014-07-18 Satadru Bag , Varun Sahni , Yuri Shtanov , Sanil Unnikrishnan

First and second order non-equilibrium thermodynamics are studied in the context of particle creation mechanism for homogeneous and isotropic FLRW model and a general formulation of the emergent scenario is investigated. Finally, the…

General Relativity and Quantum Cosmology · Physics 2017-10-19 Sourav Haldar , Pritikana Bhandari , Subenoy Chakraborty

The present work is an attempt for emergent universe scenario with modified Chaplygin gas. The universe is chosen as spatially flat FRW space-time with modified Chaplygin gas as the only cosmic substratum. It is found that emergent scenario…

General Physics · Physics 2016-01-12 Sourav Dutta , Sudeshna Mukerji , Subenoy Chakraborty

We propose a cosmological model that describes isotropic expansion of inhomogeneous universe. The energy-momentum tensor that creates the spatial inhomogeneity may not affect the uniform expansion scaling factor $a(t)$ in the FLRW-like…

High Energy Physics - Theory · Physics 2014-10-15 Wei-Jian Geng , H. Lu

In this paper, with the presence of swampland conjecture, we use the complex form of a scalar field and investigate the anisotropic constant-roll of an inflationary scenario. Recently, the complex quintessence field has been used to…

General Relativity and Quantum Cosmology · Physics 2022-03-17 Jafar Sadeghi , Saeed Noori Gashti , Mehdi Shokri

A specific class of flat Emergent Universe (EU) is considered and its viability is tested in view of the recent observations. Model parameters are constrained from Stern data for Hubble Parameter and Redshift ($H(z)$ vs. $z$) and from a…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-17 B. C. Paul , S. Ghose , P. Thakur

The observable universe is fundamentally inhomogeneous and anisotropic. Quantum description of the generation of these inhomogeneities and anisotropies is ill-understood and unsatisfactory. After providing a brief account of the standard…

General Relativity and Quantum Cosmology · Physics 2024-04-05 Sujoy K. Modak

We consider the emergent universe scenario supported by a chiral cosmological model with two interacting dark sector fields: phantom and canonical. We investigate the general properties of the evolution of the kinetic and potential energies…

General Relativity and Quantum Cosmology · Physics 2013-12-09 A. Beesham , S. V. Chervon , S. D. Maharaj , A. S. Kubasov

Closed, singularity-free, inflationary cosmological models have recently been studied in the context of general relativity. Despite their appeal, these so called emergent models suffer from a number of limitations. These include the fact…

Astrophysics · Physics 2009-11-10 David J. Mulryne , Reza Tavakol , James E. Lidsey , George F. R. Ellis

In the context of a family os scalar-tensor theories with a dynamical $\Lambda$, that is a binomial on the scalar field, the cosmological equations are considered. A general barotropic state equation $p=(\gamma-1)\rho$, for a perfect fluid…

General Relativity and Quantum Cosmology · Physics 2009-10-31 L. M. Diaz-Rivera , L. O. Pimentel

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