Event № 233
Event № 233
Type: Seminar
Name: Geometry and Topology Seminar
Title: Quasimorphisms on the Hamiltonian groups of surfaces and the Hofer metric
Speaker: Michael Khanevsky
Place:
Amado 814, Technion
Abstract:
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There are several constructions of quasimorphisms on the Hamiltonian groups of surfaces that were proposed by Gambaudo-Ghys, Polterovich, Py, etc. These constructions are based on topological invariants either of individual orbits or of orbits of finite configurations of points and the quasimorphism computes the average value of these invariants along the surface. We show that many quasimorphisms that arise this way are not Hofer continuous. This allows to show non-equivalence of Hofer's metric and some other metrics on the Hamiltonian group.
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SubmittedBy:
Seminar/Colloquium Moderator
EventLink: Event № 233