Opuscula Math. 27, no. 1 (2007), 73-81

Opuscula Mathematica

# On quasi-similarity and ω-hyponormal operators

Mourice Ouma Otieno

Abstract. In this paper, it is shown that a Putnam-Fuglede type commutativity theorem holds for $$\omega$$-hyponormal operators, the normal parts of quasi-similar $$\omega$$-hyponormal operators are unitarily equivalent and a $$\omega$$-hyponormal spectral operator is normal.

Keywords: $$\omega$$-hyponormal operators, quasi-similarity.

Mathematics Subject Classification: 47B20.

Full text (pdf)

• Mourice Ouma Otieno
• University of Nairobi, School of Mathematics, P.O. Box 30197, Nairobi, Kenya