A Topological-like Model for Gravity in 4D Space-time
  In this paper we consider a model for gravity in 4-dimensional space-time originally proposed by Chamseddine, which may be derived by dimensional reduction and truncation from a 5-dimensional Chern-Simons theory. Its topological origin makes it an interesting candidate for an easier quantization, e.g., in the Loop Quantization framework. The present paper is dedicated to a classical analysis of the model's properties. Cosmological solutions as well as wave solutions are found and compared with the corresponding solutions of Einstein's General Relativity with cosmological constant. 
Ivan Morales, Bruno Neves, Zui Oporto and Olivier Piguet
gr-qc hep-th