Slides of 5 lectures at XV Brazilian School on Cosmology and ...

I. Coarse-graining <strong>at</strong> SSHIn timescape model we will coarse-grain “dust” <strong>at</strong> SSHScale <strong>at</strong> which fluid cell properties from cell to cellremain similar on average throughout evolution <strong>of</strong>universeNotion <strong>of</strong> “comoving with dust” will require clarific<strong>at</strong>ionVariance <strong>of</strong> expansion etc rel<strong>at</strong>es more to internaldegrees <strong>of</strong> freedom <strong>of</strong> fluid particle than differencesbetween particlesCoarse-graining over internal gravit<strong>at</strong>ional degrees <strong>of</strong>freedom means th<strong>at</strong> we no longer deal with a singleglobal geometry: description <strong>of</strong> geometry is st<strong>at</strong>istical15th <strong>Brazilian</strong> <strong>School</strong> on Cosmology and Gravit<strong>at</strong>ion, August 2012 – p.21/143