A 4.ª sessão do Seminário de Matemática terá lugar no dia 13 de janeiro, pelas 14:30, na sala C104 do edifício II do ISCTE-IUL. 

A sessão estará a cargo de Maria das Neves Rebocho do Departmento de Matematica da Universidade da Beira Interior e tem como título "On classical orthogonal polynomials and some of their extensions via Sylvester equations" e o seguinte resumo:

The so-called classical orthogonal polynomials (Hermite Laguerre and Jacobi) are characterized by the Pearson differential equation for the orthogonality weight, Aw' = Cw, with A, C polynomials, or, equivalently, by the rest ODE for the corresponding Stieltjes function, AS' = CS + D (here, D is a polynomial defined in terms of A, C). 

In this talk we focus on the study of classical orthogonal polynomials in the framework of matrix Sylvester equations. Emphasis will be put on some extensions of classical orthogonal polynomials arising through perturbations of the weight w, or equivalently, arising through rational spectral transformations of the Stieltjes function S.