Quasinormal Modes of Tidally Deformed Black Holes

Compute the quasinormal mode spectrum of black holes subject to tidal perturbations from compact companions, by deriving the mode frequencies and damping rates for tidally deformed geometries and validating them through analytical and numerical methods.

Background

In discussing environmental effects, the authors model a black hole perturbed by a distant compact companion and derive geodesic and light-ring shifts due to the tidal field. They note that while geodesic properties can be computed, the quasinormal mode spectrum of the tidally deformed spacetime remains unknown.

This prevents a complete characterization of ringdown and mode excitation in realistic multi-body systems and motivates analytical derivations and full numerical simulations of tidally deformed black hole spacetimes.