Generalizations of Kaplansky Theorem Related to Linear Operators
  The purpose of this paper is to generalize a very famous result on products of normal operators, due to I. Kaplansky. The context of generalization is that of bounded hyponormal and unbounded normal operators on complex separable Hilbert spaces. Some examples "spice up" the paper. 
Abdelkader Benali and Mohammed Hichem Mortad
math.FA math.OA