  The study of BTZ blackhole physics and the cosmological horizon of 3D de
Sitter spaces are carried out in unified way using the connections to the Chern
Simons theory on three manifolds with boundary. The relations to CFT on the
boundary is exploited to construct exact partition functions and obtain
logarithmic corrections to Bekenstein formula in the asymptotic regime.
Comments are made on the dS/CFT correspondence frising from these studies.
