Anisotropic pressures at ultrastiff singularities and the stability of cyclic universes
Anisotropic pressures at ultrastiff singularities and the stability of cyclic universes
We show that the inclusion of simple anisotropic pressures stops the isotropic Friedmann universe being a stable attractor as an initial or final singularity is approached when pressures can exceed the energy density. This shows that the situation with isotropic pressures, studied earlier in the context of cyclic and ekpyrotic …