Type: Seminar

Distribution: World

Expiry: 24 May 2024

CalTitle1: Quasi-morphisms and approximate lattices

Auth: alexs@desktop-h8gjltm.staff.wireless.sydney.edu.au (ashe8718) in SMS-SAML

Michael Bjorklund (Chalmers University) is speaking in the Algebra Seminar this week. We will go out for lunch after the talk. When: Friday 1 March, 12-1pm Where: Carslaw 175 Title: Quasi-morphisms and approximate lattices Abstract: An approximate lattice is a uniformly discrete approximate subgroup Lambda of a locally compact group G for which there is a finite volume Borel set B in G such that B*Lambda = G (* is multiplication). To every such approximate lattice, one can associate a dynamical system of G, which, in the case when Lambda is a lattice coincides with the canonical G-action on the quotient space G/Lambda. In this talk we discuss how one can construct approximate lattices from (cohomologically non-trivial) quasi-morphisms, and show that the corresponding (compact) hulls do not admit any invariant probability measures, and always project to a non-trivial Furstenberg boundary. No prior knowledge of approximate lattices or quasi-morphisms will be assumed. Based on joint work with Tobias Hartnick (Karlsruhe).

Calendar (ICS file) download, for import into your favourite calendar application

UNCLUTTER for printing

AUTHENTICATE to mark the scnews item as read