English

The limiting distribution of Legendre paths

Number Theory 2024-05-07 v2 Probability

Abstract

Let pp be a prime number and (p)\left(\frac{\cdot}{p}\right) be the Legendre symbol modulo pp. The \emph{Legendre path} attached to pp is the polygonal path whose vertices are the normalized character sums 1pnj(np)\frac{1}{\sqrt{p}} \sum_{n\leq j} \left(\frac{n}{p}\right) for 0jp10\leq j\leq p-1. In this paper, we investigate the distribution of Legendre paths as we vary over the primes Qp2QQ\leq p\leq 2Q, when QQ is large. Our main result shows that as QQ \to \infty, these paths converge in law, in the space of real-valued continuous functions on [0,1][0, 1], to a certain random Fourier series constructed using Rademacher random completely multiplicative functions. This was previously proved by the first author under the assumption of the Generalized Riemann Hypothesis.

Keywords

Cite

@article{arxiv.2304.13025,
  title  = {The limiting distribution of Legendre paths},
  author = {Ayesha Hussain and Youness Lamzouri},
  journal= {arXiv preprint arXiv:2304.13025},
  year   = {2024}
}

Comments

Major modifications: we added the new Subsection 3.2 in which we describe an alternative approach to replace the convergence in the sense of finite distributions of the path by that of its Fourier coefficients. We also improved and simplified the proof of Proposition 4.5 thanks to a suggestion of one of the referees. 23 pages, to appear in Journal de l'\'Ecole polytechnique

R2 v1 2026-06-28T10:17:35.217Z