Causality violation and naked time machines in AdS(5)

We study supersymmetric charged rotating black holes in AdS(5), and show th at closed timelike curves occur outside the event horizon. Also upon liftin g to rotating D3 brane solutions of type-IIB supergravity in ten dimensions , closed timelike curves are still present. We believe that these causal an omalies correspond to loss of unitarity in the dual N = 4,D = 4 super Yang- Mills theory, i.e. the chronology protection conjecture in the AdS bulk is related to unitarity bounds in the boundary CFT. We show that no charged or uncharged geodesic can penetrate the horizon, so that the exterior region is geodesically complete. These results still hold true in the quantum case , i. e. the total absorption cross section for Klein-Gordon scalars propaga ting in the black hole background is zero. This suggests that the effective temperature is zero instead of assuming the naively found imaginary value.