Observationally homogeneous shear-free perfect fluids
type: Item
instance of: scholarly article
title: Observationally homogeneous shear-free perfect fluids
zbMATH Open document ID: 0664.76158
DOI: 10.1007/BF00758973
author: J. M. Lang
author: C. B. Collins
published in: General Relativity and Gravitation
publication date: 1988-01-01T00:00:00Z
review text: It has been conjectured that, in general relativity, shear-free perfect fluids which obey any reasonable barotropic equation of state are necessarily either nonexpanding or nonrotating. We prove that this is valid in the restricted case when the fluid's expansion and energy density are assumed to be functionally dependent. In a cosmological context, this condition of functional dependence is of interest, because it is closely related to a recently proposed criterion of observational (spatial) homogeneity, which has been enunciated in the postulate of Uniform Thermal Histories (indeed, the two are equivalent when the fluid's expansion is nonzero). Our results on shear-free fluids may be readily specialized to the case of hypersurface-homogeneous spacetimes, and in particular to that of spatially homogeneous cosmological models. We briefly examine all subcases in which the fluid's expansion is nonzero and focus attention on the one-parameter family of solutions which are not hypersurface-homogeneous.
Mathematics Subject Classification ID: 76Y05
Mathematics Subject Classification ID: 83C55
Mathematics Subject Classification ID: 83F05
zbMATH DE Number: 4087363
zbMATH Keywords: shear-free perfect fluids
zbMATH Keywords: barotropic equation of state
zbMATH Keywords: Uniform Thermal Histories
zbMATH Keywords: hypersurface-homogeneous spacetimes
describes a project that uses: Maple
MaRDI profile type: Publication
cites work: Isotropic solutions of the Einstein-Boltzmann equations
cites work: Shear-free perfect fluids in general relativity. I. Petrov type N Weyl tensor
cites work: Tilted homogeneous cosmological models
cites work: A class of shear-free perfect fluids in general relativity. I
cites work: Shear-free perfect fluids with zero magnetic Weyl tensor
full work available at URL: https://doi.org/10.1007/bf00758973
OpenAlex ID: W2004842474
description: scientific article; zbMATH DE number 4087363