English

Polynomial bounds for the Chowla Cosine Problem

Classical Analysis and ODEs 2025-09-24 v2 Combinatorics Number Theory

Abstract

Let ANA\subset \mathbf{N} be a finite set of n=An=|A| positive integers, and consider the cosine sum fA(x)=aAcosaxf_A(x)=\sum_{a\in A}\cos ax. We prove that minxfA(x)n1/7o(1),\min_x f_A(x)\leqslant -n^{ 1/7-o(1)}, thereby establishing polynomial bounds for the Chowla cosine problem.

Cite

@article{arxiv.2509.05260,
  title  = {Polynomial bounds for the Chowla Cosine Problem},
  author = {Benjamin Bedert},
  journal= {arXiv preprint arXiv:2509.05260},
  year   = {2025}
}

Comments

18 pages. New version improves the exponent to 1/7, and proves polynomial bounds for general cosine polynomials with coefficients in an arbitrary finite set

R2 v1 2026-07-01T05:23:28.194Z