Colloquium, Monday, Nov 12: Charles Smart (MIT) Title: Regularity and stochastic homogenization of fully nonlinear equations without uniform ellipticity Abstract: I will discuss regularity of fully nonlinear elliptic equations when the usual uniform upper bound on the ellipticity is replaced by bound on its $L^d$ norm, where $d$ is the dimension of the ambient space. Our estimates refine the classical theory and require several new ideas that we believe are of independent interest. As an application, we prove homogenization for a class of stationary ergodic strictly elliptic equations.