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Formation of shell-crossing singularities in effective gravitational collapse models with bounded and unbounded polymerizations

Francesco Fazzini*, Kristina Giesel†, and Eric Rullit‡

  • *Contact author: francesco.fazzini@fau.de
  • †Contact author: kristina.giesel@fau.de
  • ‡Contact author: eric.rullit@fau.de
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Phys. Rev. D 114, 086016 – Published 20 October, 2026

DOI: https://doi.org/10.1103/5nry-t25l

Abstract

We extend the investigation into the formation of shell-crossing singularities (SCSs) in effective polymerized Lemaître-Tolman-Bondi (LTB) models to the loop-quantum-gravity-inspired asymmetric bounce model, as well as to effective LTB models based on the solutions of Bardeen and Hayward, in which no bounce occurs. While the asymmetric bouncing model belongs to the class of bounded polymerization functions, the latter models feature unbounded polymerization functions. Our results show that, similar to the symmetric bouncing model, for the asymmetric bouncing model SCSs are unavoidable for inhomogeneous dust profiles. In contrast, for models without a bounce and with unbounded polymerization functions, no SCSs form for inhomogeneous, decreasing dust profiles—a situation that resembles classical theory, in which SCSs can also be avoided by a suitable choice of initial data.

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Phys. Rev. D 114, 086016– Published 20 October, 2026
  • Received 29 April 2026
  • Accepted 22 September 2026
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