Geometries with integrable singularity -- black/white holes and   astrogenic universes
  We briefly review the problem of generating cosmological flows of matter in GR (the genesis of universes), analyze models' shortcomings and their basic assumptions yet to be justified in physical cosmology. We propose a paradigm of cosmogenesis based on the class of spherically symmetric solutions with {\it integrable} singularity $r=0$. They allow for geodesically complete geometries of black/white holes, which may comprise space-time regions with properties of cosmological flows. 
V.N. Lukash and V.N. Strokov
astro-ph.CO gr-qc hep-th