Operator Algebra Seminar

Speaker:  Magnus Goffeng

Title: Unbounded Kasparov modules for Cuntz-Pimsner algebras

Abstract : In this talk we will see how to construct an explicit unbounded representative of the defining extension for a Cuntz-Pimsner algebra (associated with a finitely generated bi-Hilbert module). The motivation comes from Cuntz-Krieger algebras. When studying one-sided subshifts of finite type, the "lag" appearing in the shift tail equivalence defines an unbounded operator on the Cuntz-Krieger algebra and can be assembled to an unbounded Kasparov module. The idea behind the construction in a more general setting is to generalize this operator that measures the "lag", i.e. a type of depth below the core. This is joint work with Bram Mesland and Adam Rennie.