Entropy of Extremal Dyonic Black Holes

Abstract

For extremal charged black holes, the thermodynamic entropy is proportional not to the area but to the mass or charges. This is demonstrated here for dyonic extremal black hole solutions of string theory. It is pointed out that these solutions have zero classical action although the area is nonzero. By combining the general form of the entropy allowed by thermodynamics with recent observations in the literature it is possible to fix the entropy almost completely.

8 pages, LATEX; it is pointed out that the classical action vanishes

Cited by in corpus (5)

• The Black Branes of M-theory
• Loop-corrected Entropy of Near-extremal Dilatonic $p$-branes
• Statistical entropy of near-extremal and fundamental black p-branes
• Entropy of Scalar Field near a Schwarzschild Black Hole Horizon
• Entropy of near-extremal dyonic black holes