Black Holes in Asymptotic Safety: A Review of Solutions and Phenomenology

Abstract

Asymptotic Safety offers a conservative and predictive framework for quantum gravity, based on the existence of a renormalization group fixed point that ensures ultraviolet completeness without introducing new degrees of freedom. Black holes provide a natural arena in which to explore the implications of this scenario, as they probe the strongest gravitational fields and highlight the shortcomings of classical general relativity. In recent years, a variety of quantum-corrected black-hole solutions have been constructed within the Asymptotic Safety approach, either by renormalization-group improvement of classical metrics or through effective actions inspired by the flow of couplings. This review summarizes the current status of these developments. We discuss the structure and properties of the proposed solutions, their thermodynamics and evaporation, and their dynamical aspects such as quasinormal modes and shadows.