Quasi-normal modes of the scalar hairy black hole

We calculate quasi-normal modes of the scalar hairy black hole in the AdS background using the Horowitz–Hubeny method for the potential that is not known in an analytical form. For some black hole parameters we found pure imaginary frequencies. Increasing the scalar field mass does not cause the imaginary part to vanish, it reaches some minimum and then increases; thus, in the case under consideration, the infinitely long living modes (quasi-resonances) do not appear.