The Case Against Smooth Null Infinity and the Persistence of Polyhomogeneity

17.04.2024 14:15 - 15:45

Leonhard Kehrberger, University of Leipzig

Abstract:

In this talk, I will describe recent and upcoming work on the asymptotic behaviour of gravitational radiation (linearised gravity around Schwarzschild) in a neighbourhood of spacelike infinity including past and future null infinity. I will first set up a mathematical scattering framework in which one can understand the question of smoothness of null infinity on physical grounds. I will then use this framework to present a basic sketch of the proof of the irregularity of null infinity in various physically motivated settings, together with a complete description of the semiglobal asymptotics of gravitational radiation one obtains instead.
In particular, I will discuss how a class of asymptotic conservation laws related to the Newman-Penrose charges can be used to infer the asymptotics for fixed angular modes, and describe how to use a persistence of polyhomogeneity result to sum up the individual angular modes.

Based on joint work with Hamed Masaood and Istvan Kadar.

Organiser:
P. Chrusciel, D. Fajman
Location:

Fakt. f. Physik, SR A, 2. Stock, Währingerstr. 17, 1090 Wien