# Exact extremal statistics in the classical $1d$ Coulomb gas

## TL;DR

This paper analytically derives the probability distribution and large deviation functions for the maximum charge position in a 1D Coulomb gas, revealing a third-order phase transition and distinct fluctuations from the Tracy-Widom law.

## Contribution

It provides the first exact analytical computation of the extremal statistics in the 1D Coulomb gas, including the distribution and phase transition analysis.

## Key findings

- Typical fluctuations follow a non-trivial asymmetric scaling function.
- The distribution differs from the Tracy-Widom law for Dyson's log-gas.
- The system exhibits a third-order phase transition in the large deviation regime.

## Abstract

We consider a one-dimensional classical Coulomb gas of $N$ like-charges in a harmonic potential -- also known as the one-dimensional one-component plasma (1dOCP). We compute analytically the probability distribution of the position $x_{\max}$ of the rightmost charge in the limit of large $N$. We show that the typical fluctuations of $x_{\max}$ around its mean are described by a non-trivial scaling function, with asymmetric tails. This distribution is different from the Tracy-Widom distribution of $x_{\max}$ for the Dyson's log-gas. We also compute the large deviation functions of $x_{\max}$ explicitly and show that the system exhibits a third-order phase transition, as in the log-gas. Our theoretical predictions are verified numerically.