Heinz Langer and his Work

Indefinite Inner Product Spaces, Schur Analysis, and Differential Equations

“…A summary of Heinz' research till the late nineties can be found in the paper [18] by Aad Dijksma and Israel Gohberg, appearing in OT106, and in Aad Dijksma's Laudatio [17] in OT163. During the last 20-25 years Heinz was particularly interested in block operator matrices and their special invariant subspaces.…”