International Journal of Mathematics and Mathematical Sciences
Volume 30 (2002), Issue 7, Pages 393-397

Strongly exposed points in the unit ball of trace-class operators

Kourosh Nourouzi

Department of Mathematics, KNT University of Technology, 322 West Mirdamad, Ave. 19696, P.O. Box 15875-4416, Tehran, Iran

Received 23 April 2001; Revised 22 September 2001

Copyright © 2002 Kourosh Nourouzi. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


A theorem of Arazy shows that every extreme point of the unit ball of trace-class operators is strongly exposed. We give this result a simpler and direct proof here.