Singularities and quantum gravity

Research output: Chapter in Book/Report/Conference proceedingConference contribution

60 Scopus citations


Although there is general agreement that a removal of classical gravitational singularities is not only a crucial conceptual test of any approach to quantum gravity but also a prerequisite for any fundamental theory, the precise criteria for non-singular behavior are often unclear or controversial. Often, only special types of singularities such as the curvature singularities found in isotropic cosmological models are discussed and it is far from clear what this implies for the very general singularities that arise according to the singularity theorems of general relativity. In these lectures we present an overview of the current status of singularities in classical and quantum gravity, starting with a review and interpretation of the classical singularity theorems. This suggests possible routes for quantum gravity to evade the devastating conclusion of the theorems by different means, including modified dynamics or modified geometrical structures underlying quantum gravity. The latter is most clearly present in canonical quantizations which are discussed in more detail. Finally, the results are used to propose a general scheme of singularity removal, quantum hyperbolicity, to show cases where it is realized and to derive intuitive semiclassical pictures of cosmological bounces.

Original languageEnglish (US)
Title of host publicationCOSMOLOGY AND GRAVITATION
Subtitle of host publicationXIIth Brazilian School of Cosmology and Gravitation
Number of pages40
StatePublished - 2007
EventCOSMOLOGY AND GRAVITATION: XIIth Brazilian School of Cosmololy and Gravitation - Mangaratiba, Rio de Janeiro, Brazil
Duration: Sep 10 2006Sep 23 2006

Publication series

NameAIP Conference Proceedings
ISSN (Print)0094-243X
ISSN (Electronic)1551-7616


OtherCOSMOLOGY AND GRAVITATION: XIIth Brazilian School of Cosmololy and Gravitation
CityMangaratiba, Rio de Janeiro

All Science Journal Classification (ASJC) codes

  • General Physics and Astronomy


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