The Dirichlet Problem for Curvature Equations in Riemannian Manifolds
  We prove the existence of classical solutions to the Dirichlet problem for a class of fully nonlinear elliptic equations of curvature type on Riemannian manifolds. We also derive new second derivative boundary estimates which allows us to extend some of the existence theorems of Caffarelli, Nirenberg and Spruck [4] and Ivochkina, Trundinger and Lin [19] to more general curvature functions and less convex domains. 
Jorge H. S. de Lira and Fl\'avio F. Cruz
math.DG