6 papers
Unbounded banded matrices, shifted positive bidiagonal factorizations, and mixed-type multiple orthogonality
Amílcar Branquinho, Ana Foulquié-Moreno, Manuel Mañas
This work extends Favard-type spectral representations for banded matrices beyond the bounded setting. It assumes that, for every , there exists a shift $s_N\g…
Spectral theory for Markov chains with transition matrix admitting a stochastic bidiagonal factorization
Amílcar Branquinho, Ana Foulquié-Moreno, Manuel Mañas
The recently established spectral Favard theorem for bounded banded matrices admitting a positive bidiagonal factorization is applied to a broader class of Markov chains with bound…
Uvarov Perturbations for Multiple Orthogonal Polynomials of the Mixed Type on the Step-Line
Manuel Mañas, Miguel Rojas
Uvarov-type perturbations for mixed-type multiple orthogonal polynomials on the step line are investigated within a matrix-analytic framework. The transformations considered involv…
Matrix Bessel Biorthogonal Polynomials: A Riemann-Hilbert approach
Amílcar Branquinho, Ana Foulquié-Moreno, Assil Fradi +1
We consider matrix orthogonal polynomials related to Bessel type matrices of weights that can be defined in terms of a given matrix Pearson equation. From a Riemann-Hilbert problem…
Bidiagonal matrix factorisations related to multiple orthogonal polynomials
Amílcar Branquinho, Juan E. F. Díaz, Ana Foulquié-Moreno +2
We provide necessary and sufficient conditions for the Hessenberg recurrence matrix associated with a system of multiple orthogonal polynomials to admit a factorisation as a produc…
General Geronimus Perturbations for Mixed Multiple Orthogonal Polynomials
Manuel Mañas, Miguel Rojas
General Geronimus transformations, defined by regular matrix polynomials that are neither required to be monic nor restricted by the rank of their leading coefficients, are applied…