ACTA issues

All solutions to the relaxed commutant lifting problem

A. E. Frazho, S. ter Horst, M. A. Kaashoek

Acta Sci. Math. (Szeged) 72:1-2(2006), 299-318

Abstract. A new description is given of all solutions to the relaxed commutant lifting problem. The method of proof is also different from earlier ones, and uses only an operator-valued version of a classical lemma on harmonic majorants.

AMS Subject Classification (1991): 47A20, 47A57, 31A05, 47A56

Keyword(s): commutant lifting, positive real functions, harmonic majorants, parameterization

Received September 13, 2005, and in revised form March 14, 2006. (Registered under 5922/2009.)