Superradiant instabilities in scalar-tensor Horndeski theory
Superradiant instabilities in scalar-tensor Horndeski theory
We study the superradiance effect in a class of scalar-tensor Horndeski theory. We first study the dynamics of a massive charged scalar wave scattered off the horizon of a Reissner-Nordstr\"om black hole which, in addition to its canonical coupling to gravity, is also coupled kinetically to curvature. We find that …