Marco Bruni                                  GGI Florence, October 2006
Singularities in GR
§FRW models have a matter dominated singularity (spatial curvature negligible)
§This is non-generic: for p=wr (w<1) matter is negligible, singularities are velocity dominated, Weyl curvature dominates over Ricci curvature
§Kasner (vacuum Bianchi I) is paradigmatic
§BLK conjecture: Bianchi IX ÒmixmasterÓ (a chaotic sequence of Kasner phases) is generic
§No mixmaster for w=1 and massless scalar field
§Isotropic singularity for w>1
See Rendall and Nicolai in Ò100 years of RelativityÓ, ed. Ashtekar (World Scientific, 2005)