Szegő's theorem for matrix orthogonal polynomials
arXiv:1104.4999 · doi:10.1016/j.jat.2012.05.003
Abstract
We extend some classical theorems in the theory of orthogonal polynomials on the unit circle to the matrix case. In particular, we prove a matrix analogue of Szegő's theorem. As a by-product, we also obtain an elementary proof of the distance formula by Helson and Lowdenslager.
19 pp, typos corrected, introduction expanded