Cosmic inflation prevents singularity formation in collapse into a Hayward black hole

Abstract

We construct a (quantum mechanically) modified model for the Oppenheimer–Snyder collapse scenario where the exterior of the collapsing dust ball is a Hayward black hole spacetime and the interior is a dust Friedmann–Robertson–Walker cosmology. This interior cosmology is entirely determined by the junction conditions with the exterior black hole. It turns out to be non-singular, displaying a power-law contraction which precedes a de Sitter phase or, reversely, a power-law expansion followed by a de Sitter era. We demonstrate that cosmic inflation in the collapse setting is a mechanism that decelerates collapsing matter, thereby preventing singularity formation. We also analyse the global causal structure and the viability of the model.