Black hole in asymmetric cosmological bounce

PÉREZ, DANIELA; PEREZ BERGLIAFFA, SANTIAGO E.; ROMERO, GUSTAVO E.

ASTRONOMISCHE NACHRICHTEN

WILEY-V C H VERLAG GMBH

Año: 2021 vol. 342 p. 69 - 74

0004-6337

We determine the causal structure of the McVittie spacetime for a cosmological model with an asymmetric bounce. The analysis includes the computation of trapping horizons; regular, trapped, and antitrapped regions; and the integration of the trajectories of radial null geodesics before, during, and after the bounce. We find a trapped region since the beginning of the contracting phase up to shortly before the bounce, thus showing the existence of a black hole. When the universe reaches a certain minimum scale in the contracting phase, the trapping horizons disappear, and the central singularity becomes naked. These results suggest that neither a contracting nor an expanding universe can accommodate a black hole at all times.