English
Related papers

Related papers: Nonlinear bulk viscosity and inflation

200 papers

Particle production from vacuum fluctuations during inflation is briefly revisited. The moduli problem occurring with light particles produced at the end of inflation is addressed, namely the fact that some results are in disagreement with…

General Relativity and Quantum Cosmology · Physics 2015-06-03 Jaume de Haro , Emilio Elizalde

This study extended noncanonical warm inflation to the nonminimal derivative coupling scenario. The fundamental equations, including the evolution equations and the slow roll equations of this new framework, were derived. The enlarged…

General Relativity and Quantum Cosmology · Physics 2024-12-05 Xiao-Min Zhang , Run-Qing Zhao , Zhi-peng Peng , Xi-Bin Li , Yun-Cai Feng , Peng-Cheng Chu , Yi-Hang Xing

The density fluctuations that we observe in the universe today are thought to originate from quantum fluctuations produced during a phase of the early universe called inflation. By evolving a wavefunction describing two coupled Fourier…

General Relativity and Quantum Cosmology · Physics 2009-08-13 Dan Mazur , Jeremy S. Heyl

The purpose of the present work is two folded: (1) we propose a new mechanism for the origin of bulk viscosity in cosmological context, and then, (2) we address the thermodynamic implications of viscous cosmology based on the thermodynamics…

General Relativity and Quantum Cosmology · Physics 2025-04-02 Tanmoy Paul

We revisit the framework of axion-like inflation in view of the possibility that the coupling of the inflaton to a non-Abelian topological charge density could lead to the generation of a rapidly thermalizing heat bath. Both dispersive…

High Energy Physics - Phenomenology · Physics 2022-12-14 P. Klose , M. Laine , S. Procacci

Viscous resistance to changes in the volume of a gas arises when different degrees of freedom have different relaxation times. Collisions tend to oppose the resulting departures from equilibrium and, in so doing, generate entropy. Even for…

Astrophysics · Physics 2008-11-26 X. Chen , E. A. Spiegel

Fluid dynamics accompanies with the entropy production thus increases the local temperature, which plays an important role in charged systems such as the ion channel in biological environment and electrodiffusion in capacitors/batteries. In…

Fluid Dynamics · Physics 2017-11-09 Pei Liu , Simo Wu , Chun Liu

The basic workings of inflationary models are summarized, along with the arguments that strongly suggest that our universe is the product of inflation. The mechanisms that lead to eternal inflation in both new and chaotic models are…

Astrophysics · Physics 2007-05-23 Alan H. Guth

In the context of dark energy solutions, we consider a Friedmann-Robertson-Walker spacetime filled with a non-interacting mixture of dust and a viscous fluid, whose bulk viscosity is governed by the nonlinear model proposed in [15]. Through…

General Relativity and Quantum Cosmology · Physics 2015-06-19 G. Acquaviva , A. Beesham

We use a simple model consisting of energy-momentum tensor conservation and a Maxwell-Cattaneo equation for its viscous part to study nonlinear phenomena in a real relativistic fluid. We focus on new types of behavior without…

General Relativity and Quantum Cosmology · Physics 2021-03-31 Esteban Calzetta

Hydrodynamics provides a concise but powerful description of long-time and long-distance physics of correlated systems out of thermodynamic equilibrium. Here we construct hydrodynamic equations for nonrelativistic particles with a…

Quantum Gases · Physics 2018-12-27 Keisuke Fujii , Yusuke Nishida

Nonlinear waves in a liquid with gas bubbles are studied. Higher order terms with respect to the small parameter are taken into account in the derivation of the equation for nonlinear waves. A nonlinear differential equation is derived for…

Pattern Formation and Solitons · Physics 2013-07-09 Nikolai A. Kudryashov , Dmitry I. Sinelshchikov

Generalizing a recent work [T. Taniguchi and E. G. D. Cohen, J. Stat. Phys. 126, 1 (2006)] that was based on the Onsager-Machlup theory, a nonlinear relaxation process is considered for a macroscopic thermodynamic quantity. It is found that…

Statistical Mechanics · Physics 2009-11-13 Yuki Sughiyama , Sumiyoshi Abe

Non-linear equations of radial motion of a gas bubble in a compressible viscous liquid have been modified considering effects of viscosity and compressibility more complete than all previous works. A new set of equations has been derived…

Fluid Dynamics · Physics 2007-05-23 Ahmad Moshaii , Rasool Sadighi-Bonabi , Mohammd Taeibi-Rahni

We introduce a notion of viscosity solutions for a nonlinear degenerate diffusion equation with a drift potential. We show that our notion of solutions coincide with the weak solutions defined via integration by parts. As an application of…

Analysis of PDEs · Mathematics 2009-10-20 I. C. Kim , H. K. Lei

We describe the accelerated expansion of the late-time universe using a generalized equation of state (EoS) when account is taken of bulk viscosity. We assume a homogeneous and isotropic Friedmann-Robertson-Walker spacetime. Solutions of…

General Relativity and Quantum Cosmology · Physics 2019-08-05 I. Brevik , A. N. Makarenko , A. V. Timoshkin

We prove the well-posedness of entropy weak solutions for a class of space-discontinuous scalar conservation laws with non-local flux arising in traffic modeling. We approximate the problem adding a viscosity term and we provide $L^\infty$…

Analysis of PDEs · Mathematics 2021-05-24 Felisia Angela Chiarello , Giuseppe Maria Coclite

A new description of the dynamics of warped accretion discs is presented. A theory of fully nonlinear, slowly varying bending waves is developed, involving a proper treatment of viscous fluid dynamics but neglecting self-gravitation. The…

Astrophysics · Physics 2007-05-23 G. I. Ogilvie

We obtain a non-linear generalization of the relativistic diffusion of particles with spin. We discuss diffusion equations whose non-linearity is a consequence of quantum statistics. We show that the assumptions of the relativistic…

High Energy Physics - Theory · Physics 2011-06-20 Z. Haba

Small thermodynamic systems exhibit peculiar behavior different from that observed in long-scale systems. Non-equilibrium processes taking place in those systems are strongly influenced by the presence of fluctuations which can be large.…

Statistical Mechanics · Physics 2007-05-23 J. M. Rubi