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Ci-dessous, les différences entre deux révisions de la page.

--- symplectic [2026/03/01 19:27] – g.m
+++ symplectic [2026/04/29 00:05] (Version actuelle) – g.m
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 ===== GeNeSys: Geneva-Neuchâtel Symplectic geometry seminar =====
+**2026, April 28, Tuesday, Université de Neuchâtel**, Rue Emile-Argand 11, Room B217
+h Erman Cineli (ETH Zürich, Switzerland) "Topological entropy and Floer theory".
+Abstract:
+In this talk we discuss connections between Floer theory and dynamics of Hamiltonian systems, focusing on the barcode entropy of Hamiltonian diffeomorphisms and Reeb flows. Barcode entropy is the exponential growth rate of the number of not-too-short bars in the Floer or symplectic homology persistence module. The topological entropy bounds from above the barcode entropy and, conversely, the barcode entropy admits lower bounds coming from hyperbolic invariant sets. As a consequence, the two quantities are equal in low dimensions. The talk is based on joint work with Viktor Ginzburg, Basak Gurel and Marco Mazzucchelli.
+h Peter Albers (Universität Heidelberg) "Outer symplectic and length billiards at infinity".
+Abstract:
+We define outer symplectic and length billiards on vector spaces and discuss basic properties. The former is defined in arbitrary even dimensions, the latter in dimension 2. Both are symplectic, the former with respect to the standard symplectic form the latter not. However, both these discrete dynamical systems (actually their second iteration) far away from the billiard table can be approximated by continuous (and Hamiltonian) systems. The construction of these Hamiltonians involves in both cases symplectic polar duality. This is joint work with Ana Chavez Caliz, Lael Costa and Sergei Tabachnikov.
 **2026, March 3, Tuesday, Université de Genève**, the seminar room on the 8th floor.