Kerr-de Sitter Quasinormal Modes via Accessory Parameter Expansion

Understand

Quasinormal modes are characteristic oscillatory modes that control the relaxation of a perturbed physical system back to its equilibrium state.

• In this work, we calculate QNM frequencies and angular eigenvalues of Kerr--de Sitter black holes using a novel method based on conformal field theory.
• The spin-field perturbation equations of this background spacetime essentially reduce to two Heun's equations, one for the radial part and one for the angular part.
• We use the accessory parameter expansion of Heun's equation, obtained via the isomonodromic $\tau$-function, in order to find analytic expansions for the QNM frequencies and angular eigenvalues.