Hi: There is a math colloquium tomorrow April 7 at 3:30 PM in MS 101: Speaker: YanYan Li of Rutgers University Title: Gradient estimates for elliptic equations from composite material See below for the abstract. Refreshments at 4:30 in the department lounge. Hope to see you there, David Wright Abstract: In this talk, we discuss gradient estimates for a class of divergence form elliptic equations with piecewise smooth coefficients. Such equations arise from the study of composite materials. The novelty of these estimates is that, even though they depend on the shape and on the size of the surfaces of discontinuity of the coefficients, they are independent of the distance between these surfaces. The talk is intended for a general audience.