Some remarks on C∗-convexity

AbstractRecently the study of completely positive maps has become important to the results of Brown, Douglas, and Fillmore on Ext(), a C∗-algebra. Attempts to solve questions related to Ext have often turned into questions about the matrix algebras Mn. In this paper we wish to discuss a notion of C∗-convexity related to completely positive linear maps, to state some facts about C∗-convexity, and to ask some questions about C∗-convexity. To a large degree, the tone of this paper is expository