Riemann–Hilbert Problem for the Matrix Laguerre Biorthogonal Polynomials: The Matrix Discrete Painlevé IV

• Autor(a) principal: Branquinho, Amílcar
• Data de Publicação: 2022
• Outros Autores: Moreno, Ana Foulquié, Fradi, Assil, Mañas, Manuel
• Tipo de documento: Artigo
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10316/100132; https://doi.org/10.3390/math10081205
• topic: discrete integrable systems; matrix biorthogonal polynomials; matrix Pearson equations; non-Abelian discrete Painlevé IV equation; Riemann–Hilbert problems

In this paper, the Riemann–Hilbert problem, with a jump supported on an appropriate curve on the complex plane with a finite endpoint at the origin, is used for the study of the corresponding matrix biorthogonal polynomials associated with Laguerre type matrices of weights—which are constructed in terms of a given matrix Pearson equation. First and second order differential systems for the fundamental matrix, solution of the mentioned Riemann–Hilbert problem, are derived. An explicit and general example is presented to illustrate the theoretical results of the work. The non-Abelian extensions of a family of discrete Painlevé IV equations are discussed. © 2022 by the authors. Licensee MDPI, Basel, Switzerland.