Matrix orthogonality in the plane versus scalar orthogonality in a Riemann surface
Matrix orthogonality in the plane versus scalar orthogonality in a Riemann surface
Abstract We consider a non-Hermitian matrix orthogonality on a contour in the complex plane. Given a diagonalizable and rational matrix valued weight, we show that the Christoffel–Darboux (CD) kernel, which is built in terms of matrix orthogonal polynomials, is equivalent to a scalar valued reproducing kernel of meromorphic functions in …