On Average Properties of Inhomogeneous Fluids in General Relativity: Dust Cosmologies

摘要: For general relativistic spacetimes filled with irrotational ‘dust’ a generalized form of Friedmann's equations for an ‘effective’ expansion factor aD inhomogeneous cosmologies is derived. Contrary to the standard Friedmann equations, which hold homogeneous-isotropic cosmologies, new include ‘backreaction effect’ inhomogeneities on average model. A universal relation between ‘backreaction’ and scalar curvature also given. whose averaged spatial proportional aD-2, law governing generic domain can be found. However, as show, acts produce in course structure formation, even when starting space sections that are spatially flat average.