Dilaton gravity black holes with regular interior

TL;DR

This paper introduces a new class of regular black hole solutions in dilaton gravity theories, featuring expanding universes within their horizons, expanding understanding of black hole interiors in alternative gravity models.

Contribution

It discovers regular black hole solutions with expanding interior universes in a family of dilaton gravity theories with variable couplings.

Findings

Existence of regular black holes with expanding interior universes.

Black holes in these theories can hide expanding universes inside their horizons.

The solutions are valid within a one-parameter family of dilaton gravity models.

Abstract

In a one parameter family of dilaton gravity theories which allow the coupling of the dilaton to gravity and to a U(1) gauge field to differ, we have found the existence of everywhere regular spacetimes describing black holes hiding expanding universes inside their horizon.