On some conformally invariant fully nonlinear equations, Part II:   Liouville, Harnack and Yamabe
  The Yamabe problem concerns finding a conformal metric on a given closed Riemannian manifold so that it has constant scalar curvature. This paper concerns mainly a fully nonlinear version of the Yamabe problem and the corresponding Liouville type problem. 
Aobing Li and YanYan Li