München 2019 – scientific programme

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GR: Fachverband Gravitation und Relativitätstheorie

GR 9: Quantum Gravity (joint session MP/GR)

GR 9.1: Invited Talk

Wednesday, March 20, 2019, 17:00–17:40, HS 4

Geodesic Incomplete but Quantum Complete Spacetimes — •Stefan Hofmann — Arnold Sommerfeld Center for Theoretical Physics at LMU Munich, Germany

Important spacetimes such as black holes and Friedmann cosmologies border on space-like singularities. In the vicinity of these geodesic borders, the evolution of quantum fields is described by semigroups. Semigroups allow for a complete quantum evolution if the probabilistic measure for quantum fields to populate the geodesic border becomes zero, and if the norm of quantum states is monotonously decreasing towards the geodesic border.

It is shown that black holes are quantum complete albeit geodesic incomplete. The relation to Hawking's hidden surface is discussed. Furthermore, a quantum complete prelude to inflation is presented. The apparent clash of completeness cultures is discussed and resolved.