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Related papers: Bulk Viscous Cosmology

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Based on the conservation-dissipation formalism proposed by Zhu and collaborators we formulate a general version of the Israel-Stewart theory for relativistic fluid dynamics with bulk viscosity. Our generalization consists in allowing for a…

Analysis of PDEs · Mathematics 2022-03-14 Heiner Olbermann

If nonrelativistic dark matter and radiation are allowed to interact, reaching an approximate thermal equilibrium, this interaction induces a bulk viscous pressure changing the effective one-fluid description of the universe dynamics,…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-18 Hermano Velten , William Iania

A bulk viscosity is introduced in the formalism of modified gravity. It is shown that, on the basis of a natural scaling law for the viscosity, a simple solution can be found for quantities such as the Hubble parameter and the energy…

General Relativity and Quantum Cosmology · Physics 2012-11-26 Iver Brevik

A cosmological model with variable G and Lambda is considered in the framework of Israel-Stewart-Hiscock (ISH) causal theory. Power law as well as inflationary solutions are obtained. The gravitational constant is found to increase with…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Arbab I. Arbab , A. Beesham

In this paper, bulk viscosity is introduced in new holographic dark energy (HDE) to describe the effects of cosmic non-perfect fluid on the evolution of the universe in modified $f(R,T)$ gravity. Assuming $f(R,T)=R+\lambda T$, where $R$ is…

General Relativity and Quantum Cosmology · Physics 2018-04-17 C P Singh , Milan Srivastava

Fluctuating hydrodynamics is used to describe the total energy fluctuations of a freely evolving gas of inelastic hard spheres near the threshold of the clustering instability. They are shown to be governed by vorticity fluctuations only,…

Statistical Mechanics · Physics 2009-11-11 J. Javier Brey , A. Dominguez , M. I. Garcia de Soria , P. Maynar

An analysis is presented of the Bianchi type I cosmological models with a bulk viscosity when the universe is filled with the stiff fluid $p = \epsilon$ while the viscosity is a power function of the energy density, such as $\eta = \alpha…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Wung-Hong Huang

We explore the dynamical properties of a cosmological model that includes viscous effects in the dark matter sector of the fluid equations in a flat Friedmann-Lemaitre-Robertson-Walker (FLRW) spacetime. The bulk viscous effects are…

General Relativity and Quantum Cosmology · Physics 2022-11-14 Gilberto Aguilar-Pérez , Ana A. Avilez-López , Miguel Cruz

Based on recent perturbative and non-perturbative lattice calculations with almost quark flavors and the thermal contributions from photons, neutrinos, leptons, electroweak particles, and scalar Higgs bosons, various thermodynamic…

General Relativity and Quantum Cosmology · Physics 2021-02-26 Abdel Nasser Tawfik , Carsten Greiner

We investigate the phase space dynamics of a bulk viscosity model in the Eckart approach for a spatially flat Friedmann-Robertson-Walker universe. We have included two barotropic fluids and a dark energy component. One of the barotropic…

General Relativity and Quantum Cosmology · Physics 2014-10-29 Norman Cruz , Samuel Lepe , Yoelsy Leyva , Francisco Peña , Joel Saavedra

We explore the cosmological implications at effective level of matter creation effects in a dissipative fluid for a FLRW geometry; we also perform a statistical analysis for this kind of model. By considering an inhomogeneous Ansatz for the…

General Relativity and Quantum Cosmology · Physics 2021-01-01 Víctor H. Cárdenas , Miguel Cruz , Samuel Lepe

The theory of the inflationary multiverse changes the way we think about our place in the world. According to its most popular version, our world may consist of infinitely many exponentially large parts, exhibiting different sets of…

High Energy Physics - Theory · Physics 2024-06-19 Andrei Linde

A novel technique is used to compute the bulk viscosity of high temperature holographic gauge theory plasmas with softly broken conformal symmetry. Working in a black hole background which corresponds to a non-trivial solution to the…

High Energy Physics - Theory · Physics 2010-05-12 Amos Yarom

In the past decade, the importance of dissipation and fluctuation to inflationary dynamics has been realized and has led to a new picture of inflation called warm inflation. Although these phenomena are common to condensed matter systems,…

High Energy Physics - Phenomenology · Physics 2009-11-13 Arjun Berera

In this paper the second Lyapunov method is used to study the stability of the de Sitter phase of cosmic expansion when the source of the gravitational field is a viscous fluid. Different inflationary scenarios related with reheating and…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Luis P. Chimento , Alejandro S. Jakubi , Diego Pavon

Conformally flat tilted Bianchi type V cosmological models in presence of a bulk viscous fluid and heat flow are investigated. The coefficient of bulk viscosity is assumed to be a power function of mass density. Some physical and geometric…

General Relativity and Quantum Cosmology · Physics 2009-11-10 Anirudh Pradhan , Abha Rai

We develop a theory of viscous dissipation in one-dimensional single-component quantum liquids at low temperatures. Such liquids are characterized by a single viscosity coefficient, the bulk viscosity. We show that for a generic interaction…

Strongly Correlated Electrons · Physics 2017-07-25 K. A. Matveev , M. Pustilnik

Conformally flat tilted Bianchi type V cosmological models in presence of a bulk viscous fluid and heat flow are investigated. The coefficient of bulk viscosity is assumed to be a power function of mass density. The cosmological constant is…

General Relativity and Quantum Cosmology · Physics 2008-07-30 Anirudh Pradhan , S. K. Srivastav

In this paper we have investigated an LRS Bianchi I anisotropic cosmological model of the universe by taking time varying $G$ and $\Lambda$ in the presence of bulk viscous fluid source described by full causal non-equilibrium…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Anirudh Pradhan , Purnima Pandey , G. P. Singh , R. V. Deshpandey

Recent developments in cosmology suggest that much of the universe is in a state of explosive, accelerated expansion, called inflation. We live in a "bubble" where inflation has ended, and other bubbles with diverse properties are…

High Energy Physics - Theory · Physics 2011-08-26 Alexander Vilenkin