Előadó: Jose Luis Jaramillo (University of Dijon)
Az előadás témája: On the stability of black hole quasi-normal modes
Az előadás időpontja: 2021. január 22., péntek, 14.00
Helyszín: videokonferencia, https://cern.zoom.us/j/94782546838?pwd=a0tzTXU1TVU1NW9pY0JzbmVIMFhsQT09
Meeting ID: 947 8254 6838
In this talk we explore the issue of black hole quasi-normal mode (QNM) instability. Specifically, by adopting a hyperboloidal approach to QNMs we cast the QNM problem as an eigenvalue problem for a non-selfadjoint operator. Such operators suffer potentially of instabilities in their spectrum and this point is addressed by specific tools in non-selfadjoint spectral theory, among them the notion of pseudospectrum. At an exploratory stage prior to the full analytical study, we adopt here a numerical methodology based on pseudospectral methods. After studying the Pöschl-Teller potential as a toy model already containing the main features of the discussion, we address the black hole Schwarzschild case. As a result of our analysis, we find strong support to claim: i) the stability of the slowest decaying mode, and ii) the instability of all QNM overtones. We will conclude with a discussion of the potential implications in astrophysics and fundamental physics.