Alexey Popov, Department of Pure Math University of Waterloo
“On selfadjoint extensions of semigroups of partial isometries”
Let S be a semigroup of partial isometries acting on a complex, infinite-dimensional, sepa- rable Hilbert space. In this talk we will discuss conditions which guarantee that the selfadjoint semigroup T generated by S consists of partial isometries as well. Amongst other things, we will show that this is the case when the set of final projections of elements of S generates an abelian von Neumann algebra of uniform finite multiplicity.
This is a joint work with J.Bernik, L.Marcoux and H.Radjavi.