English

On an Erd\H{o}s-type conjecture on $\mathbb{F}_q[x]$

Number Theory 2025-10-02 v5

Abstract

P. Erd\H{o}s conjectured in 1962 that on the ring Z\mathbb{Z}, every set of nn congruence classes in Z\mathbb{Z} that covers the first 2n2^n positive integers also covers the ring Z\mathbb{Z}. This conjecture was first confirmed in 1970 by R. B. Crittenden and C. L. Vanden Eynden. Later, in 2019, P. Balister, B. Bollob\'{a}s, R. Morris, J. Sahasrabudhe, and M. Tiba provided a more transparent proof. In this paper, we follow the approach used by R. B. Crittenden and C. L. Vanden Eynden to prove the generalized Erd\H{o}s' conjecture in the setting of polynomial rings over finite fields. We prove that every set of nn cosets of ideals in Fq[x]\mathbb F_q[x] that covers all polynomials whose degree is less than nn covers the ring Fq[x]\mathbb{F}_q[x].

Keywords

Cite

@article{arxiv.2407.15146,
  title  = {On an Erd\H{o}s-type conjecture on $\mathbb{F}_q[x]$},
  author = {Rongyin Wang},
  journal= {arXiv preprint arXiv:2407.15146},
  year   = {2025}
}