activity
20242026
collaborators

9 papers

math.CA2026

Positive Bidiagonal Factorizations for Banded Markov Processes

Manuel Mañas, Manuel Mañas

An ordered positive bidiagonal factorization (PBF) is used to develop a spectral and probabilistic theory for Markov transition matrices of arbitrary finite bandwidth. The factors…

math.CA2026

Bessel-Like Multiple Orthogonal Polynomials of Mixed Type

Manuel Mañas, Manuel Mañas

This article constructs a Bessel-like family of mixed-type multiple orthogonal polynomials for a matrix weight on the unit circle. Unlike a rank-one product weight, thi…

math.CA2026

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…

math.PR2026

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…

math.CA2025

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…

math.CA2025

Bivariate multiple orthogonal polynomials of mixed type on the step-line

Manuel Mañas, Miguel Rojas, Jianwen Wu

This article studies bivariate multiple orthogonal polynomials of the mixed type on the step-line. The analysis is based on the LU factorization of a moment matrix specifically ada…