1. Department of Mathematics, Ben-Gurion University of the Negev, POB 653, 84105, Beer-Sheva, Israel 2. Université de Marne la Vallée, Unité de Formation SPI, 2 rue de la butte verte, 93166, Noisy Le Grand CEDEX, France
Abstract:
Matrix-valued functions analytic and contractive in the open unit disk (Schur functions) play an important role in system theory. They represent transfer functions of causal time-invariant dissipative systems. In this paper we show how a Schur function can still be associated to a k-periodic system. This function satisfies a certain symmetry condition (conditions (1.7) for k=2 and (4.4) for general k). We study a general bitangential interpolation problem for the Schur functions satisfying this symmetry condition.