Counting integer polynomials with several roots of maximal modulus
Volume 219 / 2025
Acta Arithmetica 219 (2025), 275-295
MSC: Primary 11C08; Secondary 11R04, 11R09
DOI: 10.4064/aa240918-12-3
Published online: 20 May 2025
Abstract
In this paper, for positive integers $H$ and $k \leq n$, we obtain some estimates on the cardinality of the set of monic integer polynomials of degree $n$ and height bounded by $H$ with exactly $k$ roots of maximal modulus. These include lower and upper bounds in terms of $H$ for fixed $k$ and $n$. We also count reducible and irreducible polynomials in that set separately. Our results imply, for instance, that the number of monic integer irreducible polynomials of degree $n$ and height at most $H$ whose $n$ roots all have the same modulus is approximately $2H$ for odd $n$, while for even $n$ there are more than $H^{n/8}$ such polynomials.
