Using symmetric space techniques, we show that closed orbits of the Iwasawa
subgroups of SO(2,l−1) naturally define singularities of a black hole causal
structure in anti-de Sitter spaces in l≥3 dimensions. In particular, we
recover for l=3 the non-rotating massive BTZ black hole. The method presented
here is very simple and in principle generalizable to any semi-simple symmetric
space.Comment: 23 pages, no figur