Showing papers by "Vlastimil Pták published in 1988"
TL;DR: In this article, the lifting problem for the intertwining relation is studied and a proof of the commutant lifting theorem based on completing matrix contractions is given, where the T's are given contractions and X is a bounded operator.
Abstract: This note is devoted to the lifting problem for the intertwining relation
$$XT_1^* = T_2 X,$$
where the T's are given contractions and X is a bounded operator. The lifting is possible if and only if X satisfies a stronger condition of boundedness introduced by the authors in a previous paper. The note includes a (partly expository) section which gives a simple proof of the commutant lifting theorem based on completing matrix contractions.
11 citations
TL;DR: The notion of intertwining matrices introduced recently by the authors is used to study Loewner matrices as discussed by the authors, which requires a careful handling of polynomials with a root at infinity.
9 citations
4 citations