Instability of regularized 4D charged Einstein-Gauss-Bonnet de-Sitter black holes

We studied the instability of regularized 4D charged Einstein-Gauss-Bonnet de-Sitter black holes under charged scalar perturbations. The unstable modes satisfy the superradiant condition, but not all of the modes satisfying the superradiant condition are unstable. The instability occurs when the cosmological constant is small and the black hole charge is not too large. The Gauss-Bonnet coupling constant further destabilizes black holes when both the black hole charge and the cosmological constant are small and further stabilizes black holes when the black hole charge is large.

Automated summary

The study focused on the instability of regularized 4D charged Einstein-Gauss-Bonnet de-Sitter black holes under charged scalar perturbations. It was found that unstable modes satisfy the superradiant condition, but not all modes satisfying this condition are unstable. The instability occurs when the cosmological constant is small and the black hole charge is not too large.