# Seminar talk, 16 December 2020

Speaker: Igor Khavkine

Title: Killing compatibility complex on Kerr spacetime

Abstract:
The Killing operator ${\displaystyle K_{ab}[v]=\nabla _{a}v_{b}+\nabla _{b}v_{a}}$ on a Lorentzian spacetime ${\displaystyle (M,g)}$ plays an important role in General Relativity (GR): it generates infinitesimal gauge symmetries of the theory. Gauge symmetry invariants play the role of physical observables. In PDE language, this translates to the following: the components of a compatibility operator for ${\displaystyle K_{ab}}$ generate all local observables for linearized GR on the background ${\displaystyle (M,g)}$. In arXiv:1910.08756 we have explicitly constructed such a compatibility operator (indeed, a full compatibility complex) on the astrophysically interesting Kerr spacetime of a rotating black hole. I will motivate and explain our approach and describe the complexity of the construction.

Language: English

Video
Slides: talk-ium.pdf