Stability of nonsingular black holes
IFT Seminar Room/Red Room Instituto de Física Teórica (IFT) -C. Nicolás Cabrera, 13-15, Fuencarral-El Pardo, Madrid, SpainWe show that nonsingular black holes (BHs) realized in nonlinear electrodynamics are always prone to Laplacian instability around the center because of a negative squared sound speed in the angular direction.