NONSTABLE ABSORPTION

摘要

Let X be a finite CW complex and B be a nonunital separable simple C*-algebra with continuous scale. We show that Ext(C(X), B) is a group, and we also characterize the neutral element of Ext(C(X), B), with further information when B has additional regularity properties. We have similar results for the unital version Ext(u)(C(X), B).