Irreducibility of random polynomials of $\mathbb{Z}[X]$

Abstract

In a recent paper, Bary-Soroker, Koukoulopoulos and Kozma proved that when $A$ is a random monic polynomial of $\mathbb{Z}[X]$ of deterministic degree $n$ with coefficients $a_j$ drawn independently according to measures $μ_j,$ then $A$ is irreducible with probability tending to $1$ as $n\to\infty$ under a condition of near-uniformity of the $μ_j$ modulo four primes (which notably happens when the $μ_j$ are uniform over a segment of $\mathbb Z$ of length $N\ge 35.$) We improve here the speed of convergence when we have the near-uniformity condition modulo more primes. Notably, we obtain the optimal bound $\mathbb{P}(A \text{ irreducible}) = 1 -O(1/\sqrt n)$ when we have near-uniformity modulo twelve primes, which notably happens when the $μ_j$ are uniform over a segment of length $N\ge 10^8.$