Creation of an inflationary universe out of black hole space–time

Abstract

We investigate the effect of a black hole as a nucleation site of a false vacuum bubble based on the Euclidean actions of relevant configurations. As a result we find a wormhole-like configuration may be spontaneously nucleated once the black hole mass falls below a critical value of order of the Hubble parameter corresponding to the false vacuum energy density. As the space beyond the wormhole throat can expand exponentially, this may be interpreted as creation of another inflationary universe in the final stage of the black hole evaporation.