Quasi-similarity of weak contractions
Quasi-similarity of weak contractions
Let <italic>T</italic> be a completely nonunitary (c.n.u.) weak contraction (in the sense of Sz.-Nagy and Foiaş). We show that <italic>T</italic> is quasi-similar to the direct sum of its <inline-formula content-type="math/mathml"> <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" alttext="upper C 0"> <mml:semantics> <mml:mrow class="MJX-TeXAtom-ORD"> <mml:msub> <mml:mi>C</mml:mi> <mml:mn>0</mml:mn> </mml:msub> </mml:mrow> <mml:annotation encoding="application/x-tex">{C_0}</mml:annotation> </mml:semantics> </mml:math> </inline-formula> part and …