Perturbations of a rotating black hole in DHOST theories

Understand

We study linear perturbations of a rotating black hole solution that has been recently discovered in degenerate higher-order scalar-tensor (DHOST) theories.

• We find a parametrization which permits the explicit resolution of the scalar perturbation while the tensor perturbation is obtained as a Teukolsky equation supplemented by an effective source term.
• The effective source term is related to the black hole hair and can be computed exactly for any value of the black hole spin.
• We discuss how the perturbations of the geometry and thus the emitted gravitational waves could be modified in comparison with general relativity.