Erik Seguin, Department of Pure Mathematics, University of Waterloo
"Amenability and stability for discrete groups"
The notion of a representation of a group on a Hilbert space can be generalized to that of an "approximate representation", in which the usual homomorphism condition is replaced by some bound on the norm distance between the operators φ(xy) and φ(x) φ(y). It is natural to ask about the stability of this class of maps: namely, when the defect of an approximate representation is small, is the approximate representation well-approximated by a genuine representation of the group? In this talk, we explore the connection between amenability and the stability of approximate representations for discrete groups.
This seminar will be held both online and in person: