2024/12/02 by Per Alexandersson, Alexandersson, Per, Nils Hemmingsson +3
Physics and Astronomy · Mathematics · #Quantum chaos and dynamical systems #Nonlinear Waves and Solitons #Spectral Theory in Mathematical Physics
paper · pdf · doi:10.48550/arxiv.2412.01643
This paper, being the sequel of [An inverse problem in Polya-Schur theory. I. Non-genegerate and degenerate operators], studies a class of linear ordinary differential operators with polynomial coefficients called exactly solvable; such an operator sends every polynomial of sufficiently large degree to a polynomial of the same degree. We focus on invariant subsets of the complex plane for such operators when their action is restricted to polynomials of a fixed degree and discover a connection between this topic and classical complex dynamics and its multi-valued counterpart. As a very special case of invariant sets we recover the Julia sets of rational functions.