International Journal of Mathematics and Mathematical Sciences
Volume 2004 (2004), Issue 53-56, Pages 2821-2834
doi:10.1155/S0161171204311312

On the Putnam--Fuglede theorem

Yin Chen

Department of Mathematical Sciences, Lakehead University, Thunder Bay P7B 5E1, ON, Canada

Abstract

We extend the Putnam-Fuglede theorem and the second-degree Putnam-Fuglede theorem to the nonnormal operators and to an elementary operator under perturbation by quasinilpotents. Some asymptotic results are also given.