Fields Notes Summer/Fall 2019 2 | Page 14

FEATURE Workshop on New Trends in Variational Models: From Superconductors to Liquid Crystals June 17-21, 2019 • Fields Institute Organizers: Stan Alama and Lia Bronsard (McMaster University), Robert Jerrard (University of Toronto), and Ihsan Topaloglu (Virginia Commonwealth University). Historically, the calculus of variations is where geometry and analysis meet physics. Geometrical ideas provide a framework to study applied problems, physical insights suggest solutions and the analyses of these solutions, in the form of nonlinear partial differential equations and measure theory. Several exciting avenues of research today continue this tradition, which extends to new applications in materials science, biology, and physiology. This workshop was at once a showcase for new methods and results in variational problems and a celebration of an influential and unifying mathematician, Peter Sternberg, on the occasion of his 60th birthday. Robert V. Kohn set the tone for the conference with his opening talk on wrinkling of elastic sheets. A difficult problem in elasticity, wrinkling combines all of the elements of ground breaking variational problems and presents daunting analytical challenges. Kohn is one of the most versatile researchers in the calculus of variations who has long been a trend-setter in the field. As Sternberg's thesis advisor, Kohn began with a timeline of 12 Sternberg's career with photos and anecdotes. Sternberg's longtime collaborator, Koby Rubinstein, also presented work on a new and challenging application of classical mathematics, the role of caustics in human vision. Geometrical optics forms an important part of mathematical history, and its application to understanding the eye and optometry has been reinvigorated by Rubinstein's recent work. Several speakers addressed the blossoming area of patterns in nonlocal interaction models. Ihsan Topaloglu gave an overview of recent progress in problems of swarming, and Rustum Choksi described the effects of anisotropy in the short-range interactions. Andrew Bernoff discussed dynamical models for the fascinating group behavior of locusts. Recent PhD, Chong Wang, presented pattern formation in block copolymers, mathematically a nonlocal isoperimetric problem. Alex Misiats also spoke on pattern formation in various nonlocal contexts, and Kevin Zumbrun gave an overview on patterns in problems driven by convection.