Young Researchers' Seminar

Exterior products of operators and superoptimal analytic approximation

by Dr Dimitrios Chiotis (SPbU and EIMI)

201 (SPbU Math & CS Dept)


SPbU Math & CS Dept


For a given matrix-valued function G, which is expressible as the sum of a bounded analytic matrix-valued function on the unit disc D and a continuous matrix-valued function on the unit circle T, we present an algorithm that yields the superoptimal approximant AG of G. The algorithm employs operator theoretic results on exterior powers of Hilbert spaces along with the compactness of certain Hankel-type operators. The talk is based on joint work with Z.A. Lykova and N.J. Young.