On sums of powers of zeros of polynomials
Abstract
Due to Girard's (sometimes called Waring's) formula the sum of the th power of the zeros of every one variable polynomial of degree , , can be given explicitly in terms of the coefficients of the monic polynomial. This formula is closely related to a known \par \noindent variable generalization of Chebyshev's polynomials of the first kind, . The generating function of these power sums (or moments) is known to involve the logarithmic derivative of the considered polynomial. This entails a simple formula for the Stieltjes transform of the distribution of zeros. Perron-Stieltjes inversion can be used to find this distribution, {\it e.g.} for .\par Classical orthogonal polynomials are taken as examples. The results for ordinary Chebyshev and polynomials are presented in detail. This will correct a statement about power sums of zeros of Chebyshev's polynomials found in the literature. For the various cases (Jacobi, Laguerre, Hermite) these moment generating functions provide solutions to certain Riccati equations.
Keywords
Cite
@article{arxiv.math/9711217,
title = {On sums of powers of zeros of polynomials},
author = {Wolfdieter Lang},
journal= {arXiv preprint arXiv:math/9711217},
year = {2016}
}