Bitangential interpolation problems for symmetric rational matrix functions Original Research Article

We develop the zero-pole structure of rational matrix functions minus sign in circle(s) that satisfy an identity of the form minus sign in circle(s)TVminus sign in circle(s) = V for some square matrix V for which V = αVT, where α = ±1. As an application we describe the set of symmetric or antisymmetric solutions of a set of bitangential interpolation conditions. Solutions of bitangential interpolation conditions satisfying other types of symmetries are also discussed.