Anisotropic matter in cosmology:locally rotationally symmetric Bianchi I and VII o models

Sloan, David (2016) Anisotropic matter in cosmology:locally rotationally symmetric Bianchi I and VII o models. Classical and Quantum Gravity, 33 (10). ISSN 0264-9381

Abstract

We examine the behaviour of homogeneous, anisotropic space-times, specifically the locally rotationally symmetric Bianchi types I and VII o in the presence of anisotropic matter. By finding an appropriate constant of the motion, and transforming the equations of motion we are able to provide exact solutions in the presence of perfect fluids with anisotropic pressures. The solution space covers matter consisting of a single perfect fluid which satisfies the weak energy condition and is rich enough to contain solutions which exhibit behaviour which is qualitatively distinct from the isotropic sector. Thus we find that there is more ‘matter that matters’ close to a homogeneous singularity than the usual stiff fluid. Example metrics are given for cosmologies whose matter sources are magnetic fields, relativistic particles, cosmic strings and domain walls.