george-hallerProf. George Haller
Professor, Institute for Mechanical Systems, ETH Zürich
Material barriers to diffusive and stochastic transport
Wednesday, April 24, 2019, 12:00pm to 1:00pm | Room 31-270

Observations of tracer transport in fluids generally reveal highly complex patterns shaped by an intricate network of transport barriers. The elements of this network appear to be universal for small diffusivities, independent of the tracer and its initial distribution. In this talk, I will first review prior, purely advective approaches to transport barrier detection. Next, I will discuss a mathematical theory to predict diffusive transport barriers and enhancers solely from the flow velocity, without reliance on expensive diffusive or stochastic simulations. This theory yields a simplified computational scheme for diffusive transport problems, such as the estimation of salinity redistribution for climate studies and the forecasting of oil spill spreads on the ocean surface. I will illustrate the results on turbulence simulations and observational ocean velocity data.

Short Bio

George Haller received his Ph.D. in Applied Mechanics at the California Institute of Technology in 1993. He then spent a year as postdoc at the Courant Institute of Mathematical Sciences at New York University, prior to joining the Division of Applied Mathematics at Brown University as Assistant Professor in 1994. In 2001, he left Brown University as Associate Professor to join the Department of Mechanical Engineering at the Massachusetts Institute of Technology, where he became Professor in 2005. While still a professor at MIT, he became the first director of Morgan Stanley's Mathematical Modeling Center in Budapest, which he headed for three years. He then joined the Department of Mechanical Engineering at McGill University in 2009, serving as Department Chair till 2011. He is currently Professor of Nonlinear Dynamics at ETH Zurich. Professor Haller has served on the editorial boards of the SIAM Journal for Mathematical Analysis, the Journal of Nonlinear Science, the Journal of Discrete and Continuous Dynamical Systems and the Zeitschrift für Angewandte Mathematik und Physik (ZAMP). His honors include a Manning Assistant Proessorship at Brown University, an Alfred P. Sloan Research Fellowship, an Albert Szent-Gyorgyi Fellowship, an ASME Thomas J.R. Hughes Young Investigator Award, an Honorary Doctorate from the Budapest University of Technology and Economics and a Faculty of Engineering Distinguished Professorship at McGill University.