Logarithmic corrections to black hole entropy: the non-BPS branch

Abstract

Abstract We compute the leading logarithmic correction to black hole entropy on the non-BPS branch of 4D $$ \mathcal{N}\ge 2 $$ N ≥ 2 supergravity theories. This branch corresponds to finite temperature black holes whose extremal limit does not preserve supersymmetry, such as the D0 − D6 system in string theory. Starting from a black hole in minimal Kaluza-Klein theory, we discuss in detail its embedding into $$ \mathcal{N}=8 $$ N = 8 , 6, 4, 2 supergravity, its spectrum of quadratic fluctuations in all these environments, and the resulting quantum corrections. We find that the c-anomaly vanishes only when $$ \mathcal{N}\ge 6 $$ N ≥ 6 , in contrast to the BPS branch where c vanishes for all $$ \mathcal{N}\ge 2 $$ N ≥ 2 . We briefly discuss potential repercussions this feature could have in a microscopic description of these black holes.