Semigroup C*-algebras arising from graphs of monoids
Monday 12th December, 2022 14:00-15:00 Maths 311B
In the talk, I will introduce a class of graphs of monoids and their semigroup C*-algebras induced by the left regular representations. These graphs of monoids give rise to some partial group actions and the related transformation groupoids. We give a detailed analysis to closed invariant subspaces and the topological freeness of the partial actions. This enables us to analyze the ideal structure and compute K-theory of the reduced semigroup C*-algebras. As an application, we construct families of pairwise non-conjugate Cartan subalgebras in UCT Kirchberg algebras.