Regular and black hole solutions to higher order curvature   Einstein--Yang-Mills--Grassmannian systems in 5 dimensions
  We construct both regular and black hole spherically symmetric solutions to the original higher curvature EYM model augmented by a Grassmannian sigma model field in $d=5$ spacetime dimensions. Unlike the original model, the new model supports regular solutions in the flat space limit. We find that a peculiar singular behaviour of the solutions in the original model, persists in the case of the modified model too. A study of the solutions to the Grassmannian model in flat space is also carried out. 
Yves Brihaye, Eugen Radu, D. H. Tchrakian