Journal of Operator Theory

Volume 70, Issue 2, Autumn 2013 pp. 495-511.

Quasisimilarity of invariant subspaces for $C_0$ operators with multiplicity two

Authors: Raphael Clouatre
Author institution: Department of Mathematics, Indiana University, 831 East 3rd Street, Bloomington, IN 47405, U.S.A.

Summary: For an operator $T$ of class $C_0$ with multiplicity two, we show that the quasisimilarity class of an invariant subspace $M$ is determined by the quasisimilarity classes of the restriction $T|M$ and of the compression $T_{M^\perp}$. We also provide a canonical form for the subspace $M$.

DOI: http://dx.doi.org/10.7900/jot.2011sep19.1937
Keywords: $C_0$ operators, invariant subspaces, quasisimilarity orbit

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