Integer-valued polynomials satisfying growth constraints

TL;DR

This paper investigates integer-valued polynomials with growth constraints, refining estimates for their quantity and identifying critical thresholds based on exponential growth and logarithmic capacity.

Contribution

It provides refined bounds on the number of such polynomials and determines the critical growth threshold using logarithmic capacity.

Findings

Refined estimates for the count of IVPs with growth constraints

Identification of a critical exponential growth threshold

Connection between growth thresholds and logarithmic capacity

Abstract

We consider polynomials which take integer values on the integers (IVPs), and satisfy an additional growth condition on the natural numbers. Elkies and Speyer, answering a question by Dimitrov, showed there is a critical exponential growth threshold, such that there are infinitely many IVPs with growth above the threshold and finitely many IVPs below that threshold (of arbitrary degree). In this paper, we give more refined estimates for the number of IVPs having exponential growth thresholds. In addition, we consider a similar problem, where there is a (not necessarily symmetric) growth condition on the integers. Notably, the critical threshold is determined by the logarithmic capacity of an explicit domain.