First and second kind paraorthogonal polynomials and their zeros
Abstract
Given a probability measure with infinite support on the unit circle , we consider a sequence of paraorthogonal polynomials vanishing at where is fixed. We prove that for any fixed distinct from , we can find an explicit independent of such that either or (or both) has no zero inside the disk , with the possible exception of . Then we introduce paraorthogonal polynomials of the second kind, denoted . We prove three results concerning and . First, we prove that zeros of and interlace. Second, for an isolated point in , we find an explicit radius such that either or (or both) have no zeros inside . Finally we prove that for such we can find an explicit radius such that either or (or both) has at most one zero inside the ball .
Cite
@article{arxiv.math/0703242,
title = {First and second kind paraorthogonal polynomials and their zeros},
author = {Manwah Lilian Wong},
journal= {arXiv preprint arXiv:math/0703242},
year = {2007}
}
Comments
To appear in the Journal of Approximation Theory