On universal C^*-algebras generated by n projections with scalar sum

Abstract

We study the universal C^*-algebras generated by n projections $p_1,>...,p_n$ subject to the relation $p_1+...p_n=\lambda 1$, $\lambda \in \mathbb{R}$. The questions of when these C^*-algebras are type I, nuclear or exact are considered. It is proved also that among these algebras there is continuum of mutually nonisomorphic ones.

arXiv comment10 pages