Speaker: Russ Caflisch, Courant Institute, NYU

Title: Optimization of the Boltzmann Equation

Abstract: The kinetics of rarefied gases and plasmas are described by the Boltzmann equation and numerically approximated by the Direct Simulation Monte Carlo (DSMC) method. We present an optimization method for DSMC, derived from an augmented Lagrangian. After a forward (in time) solution of DSMC, adjoint variables are found by a backwards solver. They are equal to velocity derivatives of an objective function, which can then be optimized. This is joint work with Yunan Yang (Cornell) and Denis Silantyev (U Colorado, Colorado Springs)

Bio: Russ Caflisch is an applied mathematician whose research is on analysis and numerical methods for physical sciences. He is known for analysis of the fluid dynamic limit in kinetic theory and of vortex sheets in incompressible flow, for mathematical modeling of epitaxial growth, and for development of Monte Carlo methods for kinetic theory and finance. He is currently director of the Courant Institute of Mathematical Sciences at New York University and was director of the Institute for Pure and Applied Mathematics (IPAM) at UCLA 2008-2017. Caflisch was born and raised in Charleston, West Virginia. He graduated from Michigan State University with a BS in mathematics in 1975, and received his PhD in mathematics in 1978 at the Courant Institute, NYU. He held faculty positions at Stanford University, NYU and UCLA, before returning to NYU in 2017. He was a recipient of a Hertz Graduate Fellowship and a Sloan Research Fellowship. He is a fellow of the Society for Industrial and Applied Mathematics, the American Mathematical Society, and the American Academy of Arts and Sciences, and is a member of the National Academy of Sciences.

This talk will be offered in a hybrid format. If you wish to participate remotely, please send an email to [email protected].