CSE Symposium Keynote

Michael Holst, University of California, San Diego

The Poisson-Boltzmann Equation: Some Unfinished Business

Tuesday, April 10, 2007, 9:00 A.M.
2240 DCL, 1304 W. Springfield Ave., Urbana, IL

Abstract

We examine a nonlinear PDE model of electrostatics phenomena arising in biophysics. Through use of a two-scale expansion we establish a number of new results for the PDE itself, such as a priori max-norm estimates. These results are then used to derive a priori and a posteriori estimates of various types for Galerkin approximations. This collection of results for the continuous and discretized problems leads to the design of a particular nonlinear approximation algorithm based on error indicators and local refinement. We prove that the adaptive algorithm converges, establishing one of only a handful of rigorous results of this type for nonlinear elliptic equations. We then shift gears and describe a somewhat strange parallelization scheme for these types of adaptive algorithms that appears to scale linearly with the number of processors. We prove that in fact this is the case (with some caveats). We finish by illustrating the adaptive algorithm with examples using the Finite Element ToolKit (FETK). This is joint work with a number of collaborators.

Biography

Professor Michael Holst received his Ph.D. in Computer Science from the University of Illinois at Urbana-Champaign in 1993. He was a Prize Research Fellow and a von Karman Instructor of Applied Mathematics at the California Institute of Technology 1993-1997, Assistant Professor at UC Irvine 1997-1998, and joined the Department of Mathematics at UCSD in 1998, where he was promoted to Associate Professor in 2000 and Full Professor in 2003. He was a UCSD Hellman Fellow in 1999, and was the recipient of an NSF CAREER Award 1999-2004 for his research in computational and applied mathematics. He is currently PI, Co-PI, and/or on the steering committees for a number of interdisciplinary research projects and centers at UCSD and elsewhere.