English

Zeros of polynomials orthogonal with respect to a signed weight

Classical Analysis and ODEs 2015-07-08 v1

Abstract

In this paper we consider the polynomial sequence (Pnα,q(x))(P_{n}^{\alpha,q}(x)) that is orthogonal on [1,1][-1,1] with respect to the weight function x2q+1(1x2)α(1x),α>1,qNx^{2q+1}(1-x^{2})^{\alpha}(1-x), \alpha>-1, q\in \mathbb N; we obtain the coefficients of the tree-term recurrence relation (TTRR) by using a different method from the one derived in \cite{kn:atia1}; we prove that the interlacing property does not hold properly for (Pnα,q(x))(P_n^{\alpha,q}(x)); and we also prove that, if xn,nα+i,q+jx_{n,n}^{\alpha+i,q+j} is the largest zero of Pnα+i,q+j(x)P_{n}^{\alpha+i,q+j}(x), x2n2j,2n2jα+j,q+j<x2n2i,2n2iα+i,q+i,0i<jn1\displaystyle x_{2n-2j,2n-2j}^{\alpha+j,q+j}< x_{2n-2i,2n-2i}^{\alpha+i,q+i}, 0\leq i<j\leq n-1.

Keywords

Cite

@article{arxiv.1507.01622,
  title  = {Zeros of polynomials orthogonal with respect to a signed weight},
  author = {M. Benabdallah and M. J. Atia and R. S. Costas-Santos},
  journal= {arXiv preprint arXiv:1507.01622},
  year   = {2015}
}

Comments

12 pages, 1 figure