Type: Article
Publication Date: 2006-01-01
Citations: 40
DOI: https://doi.org/10.3934/cpaa.2006.5.709
We prove some comparison principles for viscosity solutions of fully nonlinear degenerate elliptic equationsthat satisfy some conditions of partial non-degeneracy instead of the usual uniform ellipticity orstrict monotonicity. These resultsare applied to the well-posednessof the Dirichlet problem under suitable conditions at the characteristic points of the boundary.The examples motivating the theory are operators of the form of sum of squares of vector fields plus a nonlinear first order Hamiltonian and the Pucci operator over the Heisenberg group.