STATIC 4-DIMENSIONAL ABELIAN BLACK-HOLES IN KALUZA-KLEIN THEORY

Static, four-dimensional (4D) black holes (BH's) in (4 + n)-D Kaluza-Klein (KK) theory with Abelian isometry and a diagonal internal metric have at most one electric (Q) and one magnetic (P) charge, which can either come from the same U(1)-gauge field (corresponding to BH's in effective 5-D KK theory) or from different ones [corresponding to BH's with U(1)(M) x U(1)(E) isometry of an effective 6-D KK theory]. In the latter case, explicit nonextreme solutions have the global space-time of Schwarzschild BH's, finite temperature, and nonzero entropy. In the extreme (supersymmetric) limit the singularity becomes null, the temperature saturates the upper bound T-H = 1/(4 pi root/\QP\), and entropy is sere. A class of KK BH's with constrained charge configurations, exhibiting a continuous electric-magnetic duality, is generated by global SO(n) transformations on the above classes of the solutions.