2014/06/27 by Annamaria Montanari, Montanari, Annamaria · 1 citation
Computer Science · Mathematics · #Advanced Mathematical Modeling in Engineering #Geometric Analysis and Curvature Flows #Nonlinear Partial Differential Equations #math.AP #msc:35J70 #msc:35R05
paper · pdf · doi:10.48550/arxiv.1406.7311
arxiv created 2014/07/01 · arxiv updated 2014/07/02
We consider subelliptic equations in non divergence form of the type Lu = ∑ aij XjXiu=0, where Xj are the Grushin vector fields, and the matrix coefficient is uniformly elliptic. We obtain a scale invariant Harnack's inequality on the Xj's CC balls for nonnegative solutions under the only assumption that the ratio between the maximum and minimum eigenvalues of the coefficient matrix is bounded. In the paper we first prove a weighted Aleksandrov Bakelman Pucci estimate, and then we show a critical density estimate, the double ball property and the power decay property. Once this is established, Harnack's inequality follows directly from the axiomatic theory developed by Di Fazio, Gutierrez and Lanconelli in [6].