English

Many critical points for discrete Riesz energy on $\mathbb{T}^2$

Classical Analysis and ODEs 2025-12-30 v1

Abstract

It is widely believed that the energy functional Ep:(S2)nRE_p:(\mathbb{S}^2)^n \rightarrow \mathbb{R} Ep=i,j=1ijn1xixjp E_p = \sum_{i,j=1 \atop i \neq j}^{n} \frac{1}{\|x_i-x_j\|^p} has a number of critical points, E(x)=0\nabla E(x) = 0, that grows exponentially in nn. Despite having been extensively tested and being physically well motivated, no rigorous result in this direction exists. We prove a version of this result on the two-dimensional flat torus T2\mathbb{T}^2 and show that there are infinitely many nNn \in \mathbb{N} such that the number of critical points of Ep:(T2)nRE_p: (\mathbb{T}^2)^n \rightarrow \mathbb{R} is at least exp(cn)\exp(c \sqrt{n}) provided p5lognp \geq 5 \log{n}. We also investigate the special cases n=3,4,5n=3,4,5 which turn out to be surprisingly interesting.

Keywords

Cite

@article{arxiv.2512.23018,
  title  = {Many critical points for discrete Riesz energy on $\mathbb{T}^2$},
  author = {François Clément and Stefan Steinerberger},
  journal= {arXiv preprint arXiv:2512.23018},
  year   = {2025}
}