Fatal Effects of Charges on Stability of Black Holes in Lovelock Theory

We study the stability of static spherically symmetric charged black holes under tensor type perturbations in Lovelock theory which is a natural higher dimensional generalization of Einstein theory. We derive the master equation for tensor type perturbations and present the criterions for the stability. Examining these criterions numerically, we show that a black hole with small charge has the instability if its mass is as small as extreme mass. Combined with our previous result that neutral black hole has no dynamical instability in odd dimensions, this result suggests that charges have fatal effects on black holes in Lovelock theory.