Power, Stephen C. and Hopenwasser, A. L.
(1993)
*Classification of limits of upper triangular matrix algebras.*
Proceedings of the Edinburgh Mathematical Society, 36 (1).
pp. 107-121.
ISSN 0013-0915

## Abstract

Let Tn be the operator algebra of upper triangular n × n complex matrices. Three families of limit algebras of the form lim (Tnk) are classified up to isometric algebra isomorphism: (i) the limit algebras arising when the embeddings Tnk→Tnk+1, are alternately of standard and refinement type; (ii) limit algebras associated with refinement embeddings with a single column twist; (iii) limit algebras determined by certain homogeneous embeddings. The last family is related to certain fractal like subsets of the unit square.