https://doi.org/10.1140/epjc/s10052-020-7964-0
Regular Article - Theoretical Physics
A toy model for a baby universe inside a black hole
1
Center for Field Theory and Particle Physics and Department of Physics, Fudan University, Shanghai, 200438, People’s Republic of China
2
Shanghai Astronomical Observatory, 80 Nandan Road, Shanghai, 200030, People’s Republic of China
3
Ulugh Beg Astronomical Institute, Astronomicheskaya 33, 100052, Tashkent, Uzbekistan
4
National University of Uzbekistan, 100174, Tashkent, Uzbekistan
5
Department of Physics, Nazarbayev University, 53 Kabanbay Batyr Avenue, 010000, Astana, Kazakhstan
* e-mail: bambi@fudan.edu.cn
Received:
7
January
2020
Accepted:
23
April
2020
Published online:
7
May
2020
We present a dynamical toy model for an expanding universe inside a black hole. The model is built by matching a spherically symmetric collapsing matter cloud to an expanding Friedmann–Robertson–Walker universe through a phase transition that occurs in the quantum-gravity dominated region, here modeled with semi-classical corrections at high density. The matching is performed on a space-like hyper-surface identified by the co-moving time at which quantum–gravity induced effects halt collapse. The purpose of the model is to suggest a possible reconciliation between the observation that black holes are well described by the classical solutions and the fact that the theoretical resolution of space–time singularities leads to a bounce for the collapsing matter.
© The Author(s), 2020
