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相关论文: Emergent Universe with Interacting fluids and Gene…

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In this paper we study a model of cosmic evolution, assuming that the different components of the universe could interact between them any time. An effective equation of state (EOS) for the universe has been used as well. A particular…

宇宙学与河外天体物理 · 物理学 2010-03-17 Alberto C. Balfagon , Raul Ramirez-Satorras

We investigate the evolution of a flat Emergent Universe obtained with a non-linear equation of state (nEoS) in Einstein's general theory of Relativity. The nEoS is equivalent to three different types of barotropic cosmic fluids, which are…

广义相对论与量子宇宙学 · 物理学 2024-01-08 Bikash Chandra Roy , Anirban Chanda , Bikash Chandra Paul

We investigate a flat Emergent Universe (EU) with a nonlinear equation of state which is equivalent to three different compositions of fluids. In the EU, initially, the evolution of the universe began with no interaction, but as time…

广义相对论与量子宇宙学 · 物理学 2023-09-19 Anirban Chanda , Bikash Chandra Roy , Kazuharu Bamba , Bikash Chandra Paul

A model of an emergent universe is formulated using the mechanism of particle creation. Here the universe is considered as a non-equilibrium thermodynamical system with dissipation due to particle creation mechanism. The universe is chosen…

广义相对论与量子宇宙学 · 物理学 2015-06-19 Subenoy Chakraborty

In this paper, we consider Universe filled with two-component fluid. We study two different models. In the first model we assume barotropic fluid with the linear equation of state as the first component of total fluid. In the second model…

广义相对论与量子宇宙学 · 物理学 2014-05-01 M. Khurshudyan , B. Pourhassan , E. O. Kahya

We show that in the isentropic scenario the first order thermodynamical particle creation model gives an emergent universe solution even when the chemical potential is non-zero. However there exists no emergent universe scenario in the…

广义相对论与量子宇宙学 · 物理学 2017-05-01 Saumya Ghosh , Sunandan Gangopadhyay

In this study, we investigated the effects of incorporating barotropic fluids on cosmological solutions within the general relativity (GR) framework. We proposed a modified version of the barotropic fluid with the EoS, $p=\zeta _0 \rho…

广义相对论与量子宇宙学 · 物理学 2025-04-29 Rajdeep Mazumdar , Mrinnoy M. Gohain , Kalyan Bhuyan

Different models of universes are considered in the context of teleparallel theories. Assuming that the universe is filled by a fluid with equation of state (EoS) $P=-\rho-f(\rho)$, for different teleparallel theories and different EoS we…

广义相对论与量子宇宙学 · 物理学 2015-06-12 Jaume de Haro , Jaume Amoros

A general framework for an emergent universe scenario has been given which makes use of an equation of state. The general features of the model have also been studied and possible primordial composition of the universe have been suggested.

广义相对论与量子宇宙学 · 物理学 2009-11-11 S. Mukherjee , B. C. Paul , N. K. Dadhich , S. D. Maharaj , A. Beesham

A scenario of an emergent universe is constructed in the background of an inhomogeneous space-time model which is asymptotically (at spatial infinity) FRW space-time. The cosmic substratum consists of non-interacting two components, namely…

广义相对论与量子宇宙学 · 物理学 2016-01-18 Subhra Bhattacharya , S. Chakraborty

The emergent universe scenario provides a possible alternative to bouncing cosmology to avoid the Big Bang singularity problem. In this paper we study the realization of the emergent universe scenario by making use of Quintom matter with an…

高能物理 - 理论 · 物理学 2012-11-21 Yi-Fu Cai , Mingzhe Li , Xinmin Zhang

We show that there is a correspondence between cosmology from non-extensive thermodynamics and cosmology with fluids of redefined and generalized equation of state. We first establish the correspondence in the case of basic non-extensive…

广义相对论与量子宇宙学 · 物理学 2019-12-03 Shin'ichi Nojiri , Sergei D. Odintsov , Emmanuel N. Saridakis , R. Myrzakulov

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…

广义相对论与量子宇宙学 · 物理学 2018-06-26 Mohsen Khodadi , Kourosh Nozari

We found non singular solutions for universes filled with a fluid which obey a Generalized Equation of State of the form $P(\rho)=-A\rho+\gamma\rho^{\lambda}$. An emergent universe is obtained if $A=1$ and $\lambda =1/2$. If the matter…

广义相对论与量子宇宙学 · 物理学 2016-06-29 Felipe Contreras , Norman Cruz , Esteban González

In this work, Emergent Universe scenario has been developed in general homogeneous anisotropic model and for the inhomogeneus LTB model. In the first case, it is assumed that the matter in the universe has two components - one is perfect…

广义相对论与量子宇宙学 · 物理学 2011-11-10 Sudeshna Mukerji , Nairwita Mazumder , Ritabrata Biswas , Subenoy Chakraborty

A cosmological model of dark energy interacting with dark matter and another general component of the universe is considered. The evolution equations for coincidence parameters r and s, which represent the ratios between the dark energy and…

广义相对论与量子宇宙学 · 物理学 2009-10-08 Norman Cruz , Samuel Lepe , Francisco Pena

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…

天体物理学 · 物理学 2009-11-10 David J. Mulryne , Reza Tavakol , James E. Lidsey , George F. R. Ellis

The pivotal point of the paper is to discuss the behavior of temperature, pressure, energy density as a function of volume along with determination of caloric EoS from following two model: $w(z)=w_{0}+w_{1}\ln(1+z)$ & $…

综合物理 · 物理学 2015-03-09 Sridip Pal , Ritabrata Biswas

We suggest to generalize the dark energy equation of state (EoS) by introduction the relaxation equation for pressure which is equivalent to consideration of the inhomogeneous EoS cosmic fluid which often appears as the effective model from…

高能物理 - 理论 · 物理学 2009-09-17 Shin'ichi Nojiri , Sergei D. Odintsov

Abandoning the perfect fluid hypothesis, we investigate here the possibility that the dark energy equation of state (EoS) $w$ is a nonlinear function of the energy density $\rho$. To this aim, we consider four different EoS describing…

天体物理学 · 物理学 2009-11-13 V. F. Cardone , C. Tortora , A. Troisi , S. Capozziello
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