Stieltjes prize for Bente Hilde Bakker

VU Mathematics PhD student Bente Hilde Bakker awarded Stieltjes prize 2019/2020

01/28/2021 | 1:03 PM

The Dutch Platform for Mathematics (PWN) has awarded the Stieltjes prize for the best PhD thesis in mathematics in the Netherlands in the year 2019/20 to Bente Hilde Bakker. She received her PhD degree at Vrije Universiteit Amsterdam in September 2019, with supervisors Jan Bouwe van den Berg and Rob van der Vorst, for her thesis “Nonlinear Waves in Local and Nonlocal Media — a Topological Approach”.  The jury selected the winner from a total of 76 candidates. 

From the jury report: Bente Hilde’s thesis explores the ways in which algebraic-topological machinery, originating in the Calculus of Variations, can be used to study the existence and multiplicity of traveling wave solutions to a large class of Reaction Diffusion Equations that take nonlocal interactions into account. Inspired by Floer homology and Conley’s earlier theory of isolated invariant sets, she uses topological information to count traveling waves in Morse theoretic spirit. And by adapting Noether’s theorem to a nonlocal setting she identified new conserved quantities. The abstract theory relies on technical conditions (such as ‘transversality’) and to verify these involves hard PDE analysis, in particular Carleman estimates. It was absolutely unclear that such estimates could be derived for equations with nonlocal terms, but she managed, thus showing impressive technical skills. Bente Bakker’s very general and imaginative adaptation of the Floer-Conley methods provides a new framework for thinking about traveling waves that is bound to spawn many new investigations. She deserves the prize for the abstract approach, both elegant and efficient, for the astonishing creativity in breaking down barriers previously thought impenetrable, and, last but not least, for the potential future impact on the description and understanding of coherent structures, with applications spanning nonlinear optics, fluid dynamics, and self-organized structures in biology or sociology. One of the referees wrote: “I believe Bakker’s PhD thesis is at a level that one only sees once a decade”.