Gravitational Chern-Simons terms and black hole entropy. Global aspects
  We discuss the topological and global gauge properties of the formula for a black hole entropy due to a purely gravitational Chern-Simons term. We study under what topological and geometrical conditions this formula is well-defined. To this end we have to analyze the global properties of the Chern-Simons term itself and the quantization of its coupling. We show that in some cases the coupling quantization may interfere with the well-definiteness of the entropy formula. 
L. Bonora, M. Cvitan, P. Dominis Prester, S. Pallua, I. Smolic
hep-th gr-qc