Zu Chongzhi Mathematics Research Seminar

Date and Time (China standard time): Thursday, March 7, 11:00 am – 12:00 pm

Location: WDR 1007

Title: Symplectic geometry around (hyper)semitoric integrable systems

Speaker: Sonja Hohloch

Abstract:  Since completely integrable systems naturally induce a (singular) Lagrangian fibration and thus have a natural link to symplectic topology, there are many different aspects under which intgrable systems can be studied.

In this talk, we focus on completely integrable Hamiltonian systems on 4-dimensional symplectic manifolds that have an underlying effective Hamiltonian $S^1$-action. A very special example are toric systems, more general classes of systems are so-called semitoric and hypersemitoric ones. We will relate them to each other and present interesting new symplectic and dynamical features.

Bio: Sonja Hohloch’s main research areas are dynamical systems and symplectic geometry. After finishing her PhD in Leipzig/Germany, she spent her postdoctoral years (among others) at MSRI Berkeley/USA, Stanford/USA, IAS Princeton/USA and EPFL/Switzerland. Currently she is an associate professor at the University of Antwerp/Belgium (and Francqui research professor between 2023-2026), and vice-president of the Belgium Mathematical Society.