Sigma model of near-extreme rotating black holes and their microstates

Five-dimensional non-extreme rotating black holes with large NS-NS five-bra ne and fundamental string charge are shown to be described by a conformal s igma model, which is a marginal integrable deformation of six-dimensional S L(2,R) x SU(2) WZW model. The two WZW levels are equal to the five-brane ch arge, while the parameters of the two marginal deformations generated by th e left and right chiral SU(2) currents are proportional to the two angular momentum components of the black hole. The near-horizon description is effe ctively in terms of a free fundamental string whose tension is rescaled by the five-brane charge. The microstates are identified with those of left an d right moving superconformal string oscillations in the four directions tr ansverse to the five-brane, Their statistical entropy reproduces precisely the Bekenstein-Hawking entropy of the rotating black hole. (C) 1999 Elsevie r Science B.V.