Orthogonal polynomials, spectral measures, and absolute continuity

This paper studies the measure of orthogonality for a system of polynomials corresponding to an unbounded self-adjoint Jacobi matrix with finite row sums. Techniques of operator theory and functional analysis are used to study the spectral measure of this operator (which gives the measure of orthogonality for the system of polynomials) with a view toward obtaining results on absolute continuity.