English

Hutchinson's intervals and entire functions from the Laguerre-P\'olya class

Complex Variables 2022-12-13 v1

Abstract

We find the intervals [α,β(α)][\alpha, \beta (\alpha)] such that if a univariate real polynomial or entire function f(z)=a0+a1z+a2z2+f(z) = a_0 + a_1 z + a_2 z^2 + \cdots with positive coefficients satisfy the conditions ak12ak2ak[α,β(α)] \frac{a_{k-1}^2}{a_{k-2}a_{k}} \in [\alpha, \beta(\alpha)] for all k2,k \geq 2, then ff belongs to the Laguerre--P\'olya class. For instance, from J.I.~Hutchinson's theorem, one can observe that ff belongs to the Laguerre--P\'olya class (has only real zeros) when qk(f)[4,+).q_k(f) \in [4, + \infty). We are interested in finding those intervals which are not subsets of [4,+).[4, + \infty).

Keywords

Cite

@article{arxiv.2212.05692,
  title  = {Hutchinson's intervals and entire functions from the Laguerre-P\'olya class},
  author = {Thu Hien Nguyen and Anna Vishnyakova},
  journal= {arXiv preprint arXiv:2212.05692},
  year   = {2022}
}

Comments

10 pages