2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/121911We consider the inverse mean curvature flow in Robertson-Walker spacetimes that satisfy the Einstein equations and have a big crunch singularity and prove that under natural conditions the rescaled inverse mean curvature flow provides a smooth transition from big crunch to big bang. We also construct an example showing that in general the transition flow is only of class $C^3$.9 pages, a pdf version can also be retrieved from http://www.math.uni-heidelberg.de/studinfo/gerhardt/rw.pdf and bibtex data from http://www.math.uni-heidelberg.de/studinfo/gerhardt/bibtexcgrw.html, v2: typos correctedGeneral Relativity and Quantum CosmologyHigh Energy Physics - TheoryDifferential Geometrytext