On spectral polynomials of the Heun equation. I

  • Authors:
  • Boris Shapiro;Miloš Tater

  • Affiliations:
  • Department of Mathematics, Stockholm University, SE-106 91 Stockholm, Sweden;Nuclear Physics Institute, Academy of Sciences of the Czech Republic, CZ-250 68 e, Czech Republic

  • Venue:
  • Journal of Approximation Theory
  • Year:
  • 2010

Quantified Score

Hi-index 0.00

Visualization

Abstract

The classical Heun equation has the form {Q(z)d^2dz^2+P(z)ddz+V(z)}S(z)=0, where Q(z) is a cubic complex polynomial, P(z) is a polynomial of degree at most 2 and V(z) is at most linear. In the second half of the nineteenth century E. Heine and T. Stieltjes initiated the study of the set of all V(z) for which the above equation has a polynomial solution S(z) of a given degree n. The main goal of the present paper is to study the union of the roots of the latter set of V(z)'s when n-~. We provide an explicit description of this limiting set and give a substantial amount of preliminary and additional information about it obtained using a certain technique developed by A.B.J. Kuijlaars and W. Van Assche.