Density Questions for the Truncated Matrix Moment Problem

Abstract

Abstract For a truncated matrix moment problem, we describe in detail the set of positive definite matrices of measures μ in V 2n (this is the set of solutions of the problem of degree 2n) for which the polynomials up to degree n are dense in the corresponding space L 2 (μ). These matrices of measures are exactly the extremal measures of the set V n .