Cosmologically coupled black holes with regular horizons
Phys. Rev. D 113, 084049 – Published 22 April, 2026
DOI: https://doi.org/10.1103/zctj-d8tg
Abstract
We present the most general and exact solution of Einstein’s gravity sourced by an anisotropic fluid describing the cosmological embedding (CE) of a static and spherically symmetric object, including black holes (BHs) or exotic compact objects, without radial energy influx and in an arbitrary Friedmann-Lemaître-Robertson-Walker cosmology. This is done fully considering backreaction of the local geometry on the cosmological dynamics. Our solution is free of curvature singularities at the would-be BH event horizon, thus solving a main issue of the CE of BH solutions proposed so far. As a by-product, we derive a new CE of the Schwarzschild BH—distinct from McVittie’s original proposal—that is regular everywhere except at the central singularity.
