On the homotopy groups of the automorphism groups of Cuntz-Krieger algebras

In this paper, we first present the homotopy groups of the automorphism groups of Cuntz–Krieger algebras in terms of the underlying matrices of the Cuntz–Krieger algebras. We also show that the homotopy groups are complete invariants of the isomorphism class of the Cuntz–Krieger algebras. As a result, the isomorphism type of Cuntz–Krieger algebras are completely characterized by the group structure of the weak and strong extension groups.