|
Journal of Convex Analysis 21 (2014), No. 1, 237--252 Copyright Heldermann Verlag 2014 From the Uniform Approximation of a Solution of the PDE to the L2-Approximation of the Gradient of the Solution Kakha Shashiashvili I. Javakhishvili Tbilisi State University, Faculty of Exact and Natural Sciences, 2 University Street, Tbilisi 0186, Georgia Malkhaz Shashiashvili A. Razmadze Mathematical Institute, I. Javakhishvili Tbilisi State University, 2 University Street, Tbilisi 0186, Georgia mshashiashvili@yahoo.com We establish a new energy inequality for the difference of two semiconvex functions in a bounded open convex set D of Rn. This inequality is applied to the L2-approximation problem of the gradient of the unknown solution of the nonlinear elliptic partial differential equation provided that the latter solution is a semiconvex function in D. Keywords: Semiconvex and semiconcave functions, energy inequality, L-2-approximation, gradient of semiconvex function, convex envelope. MSC: 26B25, 35J60, 49L25 [ Fulltext-pdf (134 KB)] for subscribers only. |