C*-algebras associated to submonoids of the Thompson group F
For each k≥0 we consider the Toeplitz algebra Tλ(Mk) of the monoid Mk generated by the first k+1 generators in the infinite presentation of the Thompson group F. In this talk we will discuss some structural properties, generating sets and presentation. We construct a C*-correspondence whose associated Toeplitz algebra is canonically isomorphic to Tλ(Mk) while its Cuntz--Pimsner algebra is isomorphic to the boundary quotient ∂Tλ(Mk). We use this description to study nuclearity of these algebras. Since M1 is the free monoid on two generators, Tλ(M1) is known to be nuclear by results of Cuntz; M2 is weakly quasi-lattice ordered and nuclearity of Tλ(M2) follows from work of an Huef, Nucinkis, Sehnem and Yang. We establish nuclearity of Tλ(M3) and discuss our approach to the remaining cases. This talk is based on joint work with A. an Huef, M. Laca, B. Nucinkis and I. Raeburn.