# Symmetries of Black Hole Perturbation Theory

### APA

Solomon, A. (2022). Symmetries of Black Hole Perturbation Theory. Perimeter Institute. https://pirsa.org/22110048

### MLA

Solomon, Adam. Symmetries of Black Hole Perturbation Theory. Perimeter Institute, Nov. 03, 2022, https://pirsa.org/22110048

### BibTex

@misc{ pirsa_PIRSA:22110048, doi = {10.48660/22110048}, url = {https://pirsa.org/22110048}, author = {Solomon, Adam}, keywords = {Strong Gravity}, language = {en}, title = {Symmetries of Black Hole Perturbation Theory}, publisher = {Perimeter Institute}, year = {2022}, month = {nov}, note = {PIRSA:22110048 see, \url{https://pirsa.org}} }

Adam Solomon McMaster University

## Abstract

I discuss novel symmetries of perturbation theory around rotating and non-rotating black holes in general relativity, and discuss their origins and implications for gravitational-wave astronomy. This is motivated by two special aspects of black hole perturbations in four dimensions: isospectrality of quasinormal modes and the vanishing of tidal Love numbers. There turn out to be off-shell symmetries underlying each of these phenomena. One is a duality, which on shell reproduces the famous Chandrasekhar duality and therefore underlies isospectrality, and can be thought of as an extension of electric-magnetic duality to black hole backgrounds. The other is a set of "ladder symmetries" relating modes of different angular momentum or spin, which imply the vanishing of Love numbers. This has a geometric origin in the conformal symmetry of low-frequency modes.

Zoom link: https://pitp.zoom.us/j/93633894223?pwd=cEFRYno5WSt5NUJlOWJLdVZHWjE1QT09