4 papers
Symmetric Schur-class functions on the bidisk and Schur-class functions on the symmetrized bidisk
RadomiÅ Baran, Hugo J. Woerdeman
We present some thoughts on the relation between symmetric Schur-class functions on the bidisk and Schur-class functions on the symmetrized bidisk. Among other things, use of this…
Contractive realization theory for the annulus and other intersections of discs on the Riemann sphere
RadomiÅ Baran, Piotr Pikul, Hugo J. Woerdeman +1
We develop contractive finite dimensional realizations for rational matrix functions of one variable on domains that are not simply connected, such as the annulus. The proof uses m…
Optimal interpolation in Hardy and Bergman spaces: a reproducing kernel Banach space approach
Gilbert J. Groenewald, Sanne ter Horst, Hugo J. Woerdeman
After a review of the reproducing kernel Banach space framework and semi-inner products, we apply the techniques to the setting of Hardy spaces and Bergman spaces , $1<p…
Indefinite determinantal representations versus nonsingularities on the noncommutative d-torus
Gilbert J. Groenewald, Sanne ter Horst, Hugo J. Woerdeman
We show that for a multivariable polynomial with a determinantal representation the matrix $…