On Subscalarity of Some 2 × 2<i>M</i>-Hyponormal Operator Matrices
On Subscalarity of Some 2 × 2<i>M</i>-Hyponormal Operator Matrices
We provide some conditions for<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M1"><mml:mn>2</mml:mn><mml:mo>×</mml:mo><mml:mn>2</mml:mn></mml:math>operator matrices whose diagonal entries are<mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" id="M2"><mml:mrow><mml:mi>M</mml:mi></mml:mrow></mml:math>-hyponormal operators to be subscalar. As a consequence, we obtain that Weyl type theorem holds for such operator matrices.