On Hankel positive definite perturbations of Hankel positive definite sequences and interrelations to orthogonal matrix polynomials (Q484241)

The authors study how orthogonal matrix polynomials and related second kind polynomials which correspond to sequences generated by right(left)-sided \(\alpha\)-shifting [\textit{B. Fritzsche} et al., Linear Algebra Appl. 439, No. 12, 3893--3933 (2013; Zbl 1283.44003)] or by ``two-sided'' \(a-b\)-shifting are connected with polynomials generated by the original sequence of (matrix) moments. Furthermore, a matrix analogue of the Christoffel formula is given.