Inside a Black Hole: the illusion of a Big Bang

Black Hole (BH) and Big Bang (BB) solutions to classical General Relativity (GR) have a singularity at r=0 and are therefore non physical. The inside of the BH event horizon r_{SW}=2GM, where M is the external BH mass, can not be made of regular matter/radiation. Yet, BH of different M have been observed. What is inside r r_\Lambda? We present here a new non-singular solution to GR, which we call the BH Universe (BHU), that can model both a physical BH or a BB. The BHU consists of regular expanding matter/radiation and a false vacuum energy excess \Delta = \rho_\Lambda = \Lambda/8\pi G = \rho_{BH} so that r_{SW}=r_\Lambda. For the inside comoving observer the BHU is an homogeneous and isotropic expanding (FLRW) metric. For the outside observer, this same FLRW metric looks like a static BH with mass $M \propto \Delta^{-1/2}$. This frame duality allow us to connect two nested FLRW metrics as a new solution to GR and it also explains why our universe is expanding and not contracting. The BHU solution has some distinct observational features that can be confronted against current data. Our universe seems to be a BHU, may be one of many, older and younger, interconnected island Universes.