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Related papers: On Radiative Fluids in Anisotropic Spacetimes

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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

We consider here a spherically symmetric but inhomogeneous universe filled with a massless scalar field. The model obeys two constraints. The first one is that the gradient of the scalar field is timelike everywhere. The second constraint…

General Relativity and Quantum Cosmology · Physics 2011-04-20 Swastik Bhattacharya , Pankaj S. Joshi , Ken-ichi Nakao

Cosmological solutions are obtained in an anisotropic Kantowski-Sachs (KS) and Bianchi Type-I universes considering a cosmological constant with Skyrme fluid. Interestingly, the solutions obtained here in both the KS and Bianchi-I…

General Relativity and Quantum Cosmology · Physics 2022-06-09 Rikpratik Sengupta , B C Paul , Prasenjit Pal

The Einstein's field equations of Friedmann-Robertson-Walker universes filled with a dissipative fluid described by both the {\em truncated} and {\em non-truncated} causal transport equations are analyzed using techniques from dynamical…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Vicenç Mendez , Josep Triginer

In this work we investigate the effects of torsion in the framework of Einstein-Cartan theory in early cosmology. We study solutions for a homogeneous and isotropic relativistic Weyssenhoff spin fluid with dynamical timelike axial current,…

General Relativity and Quantum Cosmology · Physics 2009-10-01 G. de Berredo-Peixoto , E. A. de Freitas

We argue that an arbitrary general relativistic static anisotropic fluid sphere, (static and spherically symmetric but with transverse pressure not equal to radial pressure), can nevertheless be successfully mimicked by suitable linear…

General Relativity and Quantum Cosmology · Physics 2017-11-29 Petarpa Boonserm , Tritos Ngampitipan , Matt Visser

The development of radiation hydrodynamical methods that are able to follow gas dynamics and radiative transfer self-consistently is key to the solution of many problems in numerical astrophysics. Such fluid flows are highly complex, rarely…

We construct the effective field theory of a perfect fluid in the early universe. Focusing on the case where the fluid has the equation of state of radiation, we show that it may lead to corrections to the background dynamics that can…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-22 Bruno Balthazar , Pedro G. Ferreira

We present a comprehensive analytical study of radiative transfer using the method of moments and include the effects of non-isotropic scattering in the coherent limit. Within this unified formalism, we derive the governing equations and…

Earth and Planetary Astrophysics · Physics 2015-06-19 Kevin Heng , João M. Mendonça , Jae-Min Lee

We investigate the possibility that dark matter is a mixture of two non-interacting perfect fluids, with different four-velocities and thermodynamic parameters. The two-fluid model can be described as an effective single anisotropic fluid,…

General Relativity and Quantum Cosmology · Physics 2011-06-30 Tiberiu Harko , Francisco S. N. Lobo

The effective theory of the Anton-Schmidt cosmic fluid within the Debye approximation is investigated. In this picture, the universe is modeled out by means of a medium without cosmological constant. In particular, the Anton-Schmidt…

General Relativity and Quantum Cosmology · Physics 2019-02-06 Salvatore Capozziello , Rocco D'Agostino , Roberto Giambò , Orlando Luongo

We show that relativistic fluids behave as non-Newtonian fluids. First, we discuss the problem of acausal propagation in the diffusion equation and introduce the modified Maxwell-Cattaneo-Vernotte (MCV) equation. By using the modified MCV…

High Energy Physics - Phenomenology · Physics 2015-05-20 Tomoi Koide

We analyze the properties of a generic cosmological fluid described by the van der Waals equation of state. Exact solutions for the energy density evolution are found as implicit functions of the scale factor for a flat…

General Relativity and Quantum Cosmology · Physics 2016-02-11 Rudinei C. S. Jantsch , Marcus H. B. Christmann , Gilberto M. Kremer

This paper is devoted to study the Bianchi type III model in the presence of anisotropic fluid in f(R) gravity. Exponential and power-law volumetric expansions are used to obtain exact solutions of the field equations. We discuss the…

General Relativity and Quantum Cosmology · Physics 2011-02-16 M. Sharif , H. Rizwana Kausar

We consider the release and subsequent gravity-driven spreading of a finite volume of fluid in an anisotropic porous medium bounded by an impermeable substrate. When the permeability in the vertical direction is much smaller than the…

Fluid Dynamics · Physics 2023-04-24 GP Benham

A general formalism recently proposed to study Newtonian polytropes for anisotropic fluids is here extended to the relativistic regime. Thus, it is assumed that a polytropic equation of state is satisfied by, both, the radial and the…

General Relativity and Quantum Cosmology · Physics 2020-07-02 G. Abellan , E. Fuenmayor , E. Contreras , L. Herrera

We study the gravitational behaviour of a spherically symmetric radiating star when the fluid particles are in geodesic motion. We transform the governing equation into a simpler form which allows for a general analytic treatment. We find…

General Relativity and Quantum Cosmology · Physics 2009-11-13 S. Thirukkanesh , S. D. Maharaj

Focusing on the numerical aspects and accuracy we study a class of bulk viscosity driven expansion scenarios using the relativistic Navier-Stokes and truncated Israel-Stewart form of the equations of relativistic dissipative fluids in 1+1…

Nuclear Theory · Physics 2009-03-24 Etele Molnar

In this paper -- Part 2 of our series on discrete spacetime -- we first provide a review of the previously published Part 1 that included the first important steps in the development of a new model of discrete spacetime (DST): the Isotropic…

General Physics · Physics 2024-10-14 David Crouse

We investigate the early time development of the anisotropic transverse flow and spatial eccentricities of a fireball with various particle-based transport approaches using a fixed initial condition. In numerical simulations ranging from…

Nuclear Theory · Physics 2022-11-01 Nicolas Borghini , Marc Borrell , Hendrik Roch