Black hole lattices and the coarse-graining problem in general relativity

Titolo: Black hole lattices and the coarse-graining problem in general relativity

Relatore: Mikołaj Korzyński (Center for Theoretical Physics, Polish Academy of Sciences, Warsaw)

Coordinate: martedì 5 luglio, ore 17:00, aula F

Abstract: The Universe, when watched on largest scales, seems rather homogeneous. However if we take a closer look we notice small structures forming voids and overdense areas. The standard approach to this situation is to consider an idealized universe in which these have been smoothed out. Wiping out structure on fine scales is known in theoretical physics as coarse-graining. I will explain why coarse-graining is problematic in general relativity, our current theory of gravitation and geometry of the Universe, and talk about black hole lattices - interesting models to test the effects of coarse-graining in GR.