Work

Vanishing Love Numbers of Kerr-Newman Black Holes

Year: 2026
Type: preprint
Abstract: Tidal Love numbers characterize the conservative response of compact objects to external perturbations and provide a powerful probe of their nature. While the static Love numbers of Schwarzschild, Kerr, and Reissner--Nordström black holes remarkably vanish, the tidal response of a generic Kerr--Newman black hole has remained unexplored due to the intrinsic coupling between gravitational and electromagnetic perturbations. Exploiting a recent breakthrough in the separability of these perturbations, we analytically determine the static tidal response of the most general stationary black hole in four-dimensional Einstein--Maxwell theory. For arbitrary multipole order, charge, and spin, we show that the entire matrix of conservative Love numbers vanishes, including the mixed gravito-electromagnetic couplings. We also compute the nonvanishing static dissipative response induced by frame dragging.
Language: English
Open Access status: green
OpenAlex ID: W7221773422
Cites: 35
Cited by: 3
Related to: 10