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In order to study if the bulk viscosity may induce a big rip singularity on the flat FRW cosmologies, we investigate dissipative processes in the universe within the framework of the standard Eckart theory of relativistic irreversible…

High Energy Physics - Theory · Physics 2008-11-26 Mauricio Cataldo , Norman Cruz , Samuel Lepe

The present work deals with a cosmological model having particle creation mechanism in the framework of irreversible thermodynamics. In the second order non-equilibrium thermodynamical prescription, the particle creation rate is treated as…

General Relativity and Quantum Cosmology · Physics 2015-05-01 Subenoy Chakraborty , Supriya Pan , Subhajit Saha

We perform a study both statistical and theoretical for cosmological models of matter creation and their ability to describe effective phantom models of dark energy. Such models are beyond the $\Lambda$CDM model since the resulting cosmic…

General Relativity and Quantum Cosmology · Physics 2020-04-23 Víctor H. Cárdenas , Miguel Cruz , Samuel Lepe , Shin'ichi Nojiri , Sergei D. Odintsov

This paper deals with gravitational thermodynamics on the dynamical apparent horizon of an FLRW universe with dissipation. The dissipation is assumed to arise due to adiabatic gravitational particle creation. For the thermodynamic study, we…

General Relativity and Quantum Cosmology · Physics 2025-02-24 Somnath Saha , Subhajit Saha , Nilanjana Mahata

We investigate the fate of particle production in an expanding universe dominated by a perfect fluid with equation of state $p = \alpha\rho$. The rate of particle production, using the Bogolioubov coefficients, are determined exactly for…

General Relativity and Quantum Cosmology · Physics 2012-07-06 A. B. Batista , J. C. Fabris , M. J. S. Houndjo

We present a novel cosmological framework that unifies matter creation dynamics with thermodynamic principles. Starting with a single-component fluid characterized by a constant equation of state parameter, $\omega$, we introduce a…

Cosmology and Nongalactic Astrophysics · Physics 2025-01-27 Víctor H. Cárdenas , Samuel Lepe

In this work we explore the thermodynamic aspects of dark energy for late future time universe in two different scenarios: as a perfect fluid with constant and variable equation of state parameter; and as dissipative fluid described by a…

General Relativity and Quantum Cosmology · Physics 2022-03-03 David Tamayo

The bulk viscosity of cosmological fluid and the creation of cold dark matter both result in the generation of irreversible entropy (related to dissipative processes) in a homogeneous and isotropic universe. To consider such effects, the…

Cosmology and Nongalactic Astrophysics · Physics 2014-12-16 Nobuyoshi Komatsu , Shigeo Kimura

In the present work, flat FRW model of the universe is considered to be an isolated open thermodynamical system where non-equilibrium prescription has been studied using the mechanism of particle creation. In the perspective of recent…

General Physics · Physics 2016-05-17 Subhajit Saha , Atreyee Biswas , Subenoy Chakraborty

We discuss the dynamical effects of bulk viscosity and particle creation on the early evolution of the Friedmann -Robertson -Walker model in the framework of open thermodynamical systems. We consider bulk viscosity and Particle creation as…

General Relativity and Quantum Cosmology · Physics 2015-03-02 C. P. Singh

Combining the equivalence between cosmological particle creation and an effective viscous fluid pressure with the fact that the latter represents a dynamical degree of freedom within the second-order Israel-Stewart theory for imperfect…

Astrophysics · Physics 2009-10-31 Winfried Zimdahl

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…

General Relativity and Quantum Cosmology · Physics 2016-01-18 Subhra Bhattacharya , S. Chakraborty

A variety of conditions is considered under which the cosmic dark fluid may be able to develop a future Big Rip or Little Rip singularity. Both one-component and two-component models are considered. In the last-mentioned case we present a…

General Relativity and Quantum Cosmology · Physics 2012-09-25 I. Brevik , R. Myrzakulov , S. Nojiri , S. D. Odintsov

Non-conservation of dark matter can lead to late-time cosmic acceleration. This mechanism is known as the matter creation theory and this replaces the need of dark energy and modified gravity theories. We consider a two-fluid system…

General Relativity and Quantum Cosmology · Physics 2025-12-02 Sudip Halder , Jaume de Haro , Supriya Pan , Tapan Saha , Subenoy Chakraborty

We study particle creation in the presence of bulk viscosity of cosmic fluid in the early universe within the framework of open thermodynamical systems. Since the first-order theory of non-equilibrium thermodynamics is non-causal and…

General Relativity and Quantum Cosmology · Physics 2015-04-30 Mehdi Eshaghi , Nematollah Riazi , Ahmad Kiasatpour

The paper deals with the mechanism of particle creation in the framework of irreversible thermodynamics. The second order non-equilibrium thermodynamical prescription of Israel and Stewart has been presented with particle creation rate,…

General Relativity and Quantum Cosmology · Physics 2016-05-04 Subenoy Chakraborty , Subhajit Saha

Evolution of the bulk viscous matter dominated universe has been analysed using the full causal, Israel-Stewart theory for the evolution of bulk viscous pressure in the context of recent acceleration of the universe. The form of bulk…

General Relativity and Quantum Cosmology · Physics 2018-04-23 Jerin Mohan N D , Athira Sasidharan , Titus K Mathew

Fluids often display dissipative properties. We explore dissipation in the form of bulk viscosity in the cold dark matter fluid. We constrain this model using current data from supernovae, baryon acoustic oscillations and the cosmic…

Cosmology and Nongalactic Astrophysics · Physics 2012-10-02 Hermano Velten , Dominik J. Schwarz

In this paper we present two concrete models of non-perfect fluid with bulk viscosity to interpret the observed cosmic accelerating expansion phenomena, avoiding the introduction of exotic dark energy. The first model we inspect has a…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 Xin-he Meng , Zhi-yuan Ma

We consider a cosmological model dominated by stiff fluid with a constant bulk viscosity. We classify all the possible cases of the universe predicted by the model and analyzing the scale factor, density as well as the curvature scalar. We…

General Relativity and Quantum Cosmology · Physics 2015-06-19 Titus K Mathew , Aswathy M B , Manoj M
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