Speaker
Jerome Quintin
(Albert Einstein Institute)
Description
In the approach to a singularity in general relativity, spacetime often becomes largely shear dominated and highly anisotropic. Any speculative cosmological scenario with a contracting phase prior to a Big Bounce must therefore address the issue of large anisotropies. In this talk, I will review this anisotropy problem and the status of isotropisation mechanisms in this context, which involve, e.g., modified gravity or non-perfect fluids. An emphasis will be given on the latter, in light of the recent work arXiv:2109.11701 [gr-qc].