English

Discrete entropies of orthogonal polynomials

Classical Analysis and ODEs 2007-10-12 v1 Information Theory Mathematical Physics math.IT math.MP

Abstract

Let pnp_n be the nn-th orthonormal polynomial on the real line, whose zeros are λj(n)\lambda_j^{(n)}, j=1,...,nj=1, ..., n. Then for each j=1,...,nj=1, ..., n, Ψj2=(Ψ1j2,...,Ψnj2) \vec \Psi_j^2 = (\Psi_{1j}^2, ..., \Psi_{nj}^2) with Ψij2=pi12(λj(n))(k=0n1pk2(λj(n)))1,i=1,>...,n, \Psi_{ij}^2= p_{i-1}^2 (\lambda_j^{(n)}) (\sum_{k=0}^{n-1} p_k^2(\lambda_j^{(n)}))^{-1}, \quad i=1, >..., n, defines a discrete probability distribution. The Shannon entropy of the sequence {pn}\{p_n\} is consequently defined as Sn,j=i=1nΨij2log(Ψij2). \mathcal S_{n,j} = -\sum_{i=1}^n \Psi_{ij}^{2} \log (\Psi_{ij}^{2}) . In the case of Chebyshev polynomials of the first and second kinds an explicit and closed formula for Sn,j\mathcal S_{n,j} is obtained, revealing interesting connections with the number theory. Besides, several results of numerical computations exemplifying the behavior of Sn,j\mathcal S_{n,j} for other families are also presented.

Keywords

Cite

@article{arxiv.0710.2134,
  title  = {Discrete entropies of orthogonal polynomials},
  author = {A. I. Aptekarev and J. S. Dehesa and A. Martinez-Finkelshtein and R. Yañez},
  journal= {arXiv preprint arXiv:0710.2134},
  year   = {2007}
}

Comments

26 pages, 6 figures

R2 v1 2026-06-21T09:30:08.101Z