Seminár Katedry teoretickej fyziky - Martin Krššák (12.12.2023)
v utorok 12.12.2023 o 14:00 hod. v miestnosti F2/125
Od: Peter Maták
Prednášajúci: Martin Krššák
Názov: Bulk gravitational action and teleparallel geometry
Termín: 12.12.2023, 14:00 hod., miestnosť F2 125
The action is a crucially important concept in physics, used to derive field equations and serving as the starting point for quantization. In general relativity, the original action introduced by Hilbert yields field equations but overlooks surface terms necessary for a consistent variational principle. In the 1970s, Gibbons and Hawking demonstrated that the Hilbert action needs to be supplemented with a surface term that plays a crucial role in path integral quantization and derivation of black hole entropy. I will briefly introduce these results, incorporating newer motivation from the holographic principle and the study of the black hole information paradox. Subsequently, I will demonstrate how this problem can be approached using the so-called bulk actions, also known as Einstein or Moller actions. While these actions do avoid some problems of Gibbons and Hawking, they are not covariant. I will then argue that these actions can be naturally cast into a covariant form using another of Einstein's inventions known as teleparallel geometry.