English

Generalization and development of the Malliavin-Rubel theorem on small entire functions of exponential type with given zeros

Complex Variables 2020-05-13 v1

Abstract

Previously, we developed the technique of balayage of measures or charges and (δ\delta-)subharmonic functions of finite order onto an closed system of rays SS with a vertex at zero on the complex plane C\mathbb C. In this article, we use only two kinds of balayage of measure and charge, as well as of subharmonic functions of finite type under the order 11 and their differences. First, it is a classical balayage of the genus q=0q=0 on a system of four closed rays: positive and negative, and real and imaginary semi-axis R+\mathbb R^+, R+-\mathbb R^+, iR+i\mathbb R^+, iR-i\mathbb R. Second, it is two-sided balayage of genus q=1q=1 from the open right and left half-planes Crh\mathbb C_{{\rm rh}} and Clh\mathbb C_{{\rm lh}} onto the imaginary axis iRi\mathbb R. The classical Malliavin-Rubel theorem gives necessary and sufficient conditions of the existence of an entire function of exponential type (we write e.f.e.t.) f≢0f\not\equiv 0, vanishing on the given positive sequence Z={zk}kNR+{\sf Z}=\{{\sf z}_k\}_{k\in \mathbb N}\subset \mathbb R^+ and satisfying the constraint fg|f|\leq |g| on iRi\mathbb R, where gg is an e.f.e.t., vanishing on positive sequence W={wk}kNR+{\sf W}=\{{\sf w}_k\}_{k\in \mathbb N}\subset \mathbb R^+. A combination of these special balayage processes of genus q=0q=0 and q=1q=1 allows us to extend the Malliavin-Rubel theorem to arbitrary complex sequences Z={zk}kNC{\sf Z}=\{{\sf z}_k\}_{k\in \mathbb N}\subset \mathbb C separated by a pair of vertical angles from the imaginary axis iRi\mathbb R, with much more general restrictions lnfM\ln |f|\leq M on the imaginary axis iRi\mathbb R, where MM is an subharmonic function of finite type under the order 11.

Keywords

Cite

@article{arxiv.2005.05781,
  title  = {Generalization and development of the Malliavin-Rubel theorem on small entire functions of exponential type with given zeros},
  author = {B. N. Khabibullin and A. E. Salimova},
  journal= {arXiv preprint arXiv:2005.05781},
  year   = {2020}
}

Comments

32 pages, in Russian