Optimal prediction of underresolved dynamics by Raz Kupferman, Department of Mathematics Lawrence Berkeley Laboratory and UC Berkeley INSCC 110, 3:30pm Monday, May 18th, 1998 Abstract There are many problems in science whose solution is described by a set of differential equations, but where the solution of these equations cannot be found, even numerically, because it cannot be properly resolved. We present a method for computing the average solution of problems which are too complicated for adequate resolution, but where information about the statistics of the solution is available. The method involves computing average derivatives by interpolation based on linear regression, and an updating of a measure constrained by the available crude information. Two examples will be given: a linear and a nonlinear Schrodinger equation. Requests for preprints and reprints to: raz@snake.lbl.gov This source can be found at http://www.math.utah.edu/applied-math/