English

Counting Equilibria of the Electrostatic Potential

Computational Geometry 2025-03-24 v2 Mathematical Physics Combinatorics math.MP

Abstract

In 1873, James C. Maxwell conjectured that the electric field generated by nn point charges in generic position has at most (n1)2(n-1)^2 isolated zeroes. The first (non-optimal) upper bound was only obtained in 2007 by Gabrielov, Novikov and Shapiro, who also posed two additional interesting conjectures. In this article, we give the best upper bound known to date on the number of zeroes of the electric field, and construct a counterexample to a conjecture of Gabrielov, Novikov and Shapiro that the number of equilibria cannot exceed those of the distance function defined by the unit point charges. Finally, we note that it is quite possible that Maxwell's quadratic upper bound is not tight, so it is prudent to find smaller bounds. Hence, we also explore examples and construct configurations of charges achieving the highest ratios of the number of electric field zeroes by point charges found to this day.

Cite

@article{arxiv.2501.05315,
  title  = {Counting Equilibria of the Electrostatic Potential},
  author = {Herbert Edelsbrunner and Christopher Fillmore and Gonçalo Oliveira},
  journal= {arXiv preprint arXiv:2501.05315},
  year   = {2025}
}

Comments

This new version contains a further major development, a new improved upper bound on the number of equilibria to the electrostatic potential

R2 v1 2026-06-28T21:01:27.734Z