ACTA issues

Littlewood--Richardson sequences associated with $C_0$-operators

Wing Suet Li, Vladimír Müller

Acta Sci. Math. (Szeged) 64:3-4(1998), 609-625

Abstract. We generalize the concept of the Littlewood-Richardson sequence associated with an invariant subspace of a nilpotent operator on a finite dimensional vector space to the context of $C_0$-contractions. The similarity invariants of nilpotent operators (decreasing sequences of sizes of the Jordan blocks) are replaced by the quasisimilarity invariants of $C_0$-contractions (sequences of inner functions).

AMS Subject Classification (1991): 47A45, 47A20, 15A23

Keyword(s): Littlewood-Richardson sequences, similarity, Jordan models, $C_0$-invariant subspaces of operators in the class

Received November 3, 1997. (Registered under 3312/2009.)