On kernel polynomials and self perturbation of orthogonal polynomials

Abstract

Given an orthogonal polynomial system $(Q_n(x))_{n=0} infty$, define another polynomial system by where αn are complex numbers and t is a positive integer. We find conditions for $(P_n(x))_{n=0} infty$ to be an orthogonal polynomial system. When t=1 and α1≠0, it turns out that $(Q_n(x))_{n=0} infty$ must be kernel polynomials for $(P_n(x))_{n=0} infty$ for which we study, in detail, the location of zeros and semi-classical character.