Superradiant instability of Kerr-de Sitter black holes in scalar-tensor theory

Understand

We investigate in detail the mechanism of superradiance to render the instability of Kerr-de Sitter black holes in scalar-tensor gravity.

• Our results provide more clues to examine the scalar-tensor gravity in the astrophysical black holes in the universe with cosmological constant.
• We also discuss the spontaneous scalarization in the de Sitter background and find that this instability can also happen in the spherical de Sitter configuration in a special style.