Chakrabarty, HrishikeshAbdujabbarov, AhmadjonMalafarina, DanieleBambi, Cosimo2021-04-122021-04-122020-05Chakrabarty, H., Abdujabbarov, A., Malafarina, D., & Bambi, C. (2020). A toy model for a baby universe inside a black hole. The European Physical Journal C, 80(5). https://doi.org/10.1140/epjc/s10052-020-7964-01434-6044https://doi.org/10.1140/epjc/s10052-020-7964-0https://link.springer.com/article/10.1140/epjc/s10052-020-7964-0http://nur.nu.edu.kz/handle/123456789/5356We 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.enAttribution-NonCommercial-ShareAlike 3.0 United Statesblack holebaby universetoy modelResearch Subject Categories::NATURAL SCIENCESResearch Subject Categories::NATURAL SCIENCES::PhysicsArticle