Nonperturbative quantum gravity denounces singular black holes

Abstract

General relativity predicts the presence of a singularity inside of a black hole revealing that it is not a complete theory of gravity. A real structure of a black hole interior near an expected singularity depends on the UV completion of gravity. In this paper we address the question of whether singular spherically symmetric solutions are absent (or present) in a complete gravity theory. We find that the answer is governed by the functional form of a nonperturbative graviton propagator. A ghost-free infinite derivative gravity is favored by the unitarity the graviton propagator of an exponential form. We explicitly show in this framework that a singularity is not possible unless an unphysical situation when a mass of the black hole is infinite is considered. Published by the American Physical Society 2025