From low-dimensional topology to symplectic dynamics
On the occasion of the 60th birthday of
Prof. Hansjörg Geiges
Cologne, 26 June 2026
On the occasion of the 60th birthday of
Prof. Hansjörg Geiges
Cologne, 26 June 2026
Leonid Polterovich (Tel Aviv)
Felix Schlenk (Neuchâtel)
Karl Friedrich Siburg (Dortmund)
9:50 - 10:00 Welcome
10:00 - 10:50 Leonid Polterovich
Contact topology meets thermodynamics
Abstract: I discuss the appearance of certain notions and results from contact topology in both equilibrium and non-equilibrium thermodynamics. These include non-smooth Legendrian submanifolds, Reeb chords, and the partial order on the space of Legendrians. Based on joint work with Michael Entov and Lenya Ryzhik.
11:00 - 11:50 Felix Schlenk
Symplectic embeddings by singular methods
Abstract: Singular methods have recently brought much progress about symplectic embedding problems (such as finding exotic Lagrangian tori, exotic cube or "almost ball"' embeddings, and staircases). This is in two ways: Certain singular spaces, in which the embeddings are obvious, can be smoothed to (for instance) CP2; and singular J-curves are used to distinguish embeddings. My talk is based on work of Adaloglou, Bargallo i Gomez, Brendel, Evans, Hauber, McDuff, Mikhalkin, Schmitz, Siegel and myself.
12:00 - 14:00 Lunch and coffee break
14:00 - 14:50 Karl Friedrich Siburg
Back to the roots
Abstract: Along the route we will encounter some people and places from the past, as well as a little lost gem from celestial mechanics.
Mathematisches Institut, Universität zu Köln, Weyertal 86-90, 50931 Köln
Registration is free but mandatory for external participants. Please contact George Marinescu: gmarines@math.uni-koeln.de
Peter Albers, George Marinescu, Eva Miranda, Kai Zehmisch