## 月曜解析セミナー： Cohomology of higher rank graphs and twisted k-graph C*-algebras

2012年 　 3月 19日 14時 45分 ～ 2012年 　 3月 19日 16時 15分

We introduce a homology theory and the corresponding cohomology theory of a
higher rank graph (inspired by the cubical homology which appears in
Massey's text). We  define the C*-algebra of a higher rank graph twisted by
a two-cocycle which takes values in the circle and derive some basic
properties.  Any  noncommutative torus and the crossed product of O_n by a
quasifree automorphism are simple examples of the C*-algebras that can
arise from this construction.

(Joint work with David Pask and Aidan Sims).