# Gaussian unitary ensemble with boundary spectrum singularity and $\sigma$-form of the Painlev\'{e} II equation

## TL;DR

This paper analyzes the asymptotic behavior of the Gaussian unitary ensemble with boundary spectrum singularities, revealing connections to Painlevé equations and deriving limits for eigenvalue distributions.

## Contribution

It introduces a novel analysis of perturbed Gaussian ensembles with boundary singularities, linking asymptotics to Painlevé equations and deriving new double scaling limits.

## Key findings

- Asymptotics of Hankel determinants expressed via Painlevé XXXIV and Painlevé II equations.
- Double scaling limits of eigenvalue distributions and correlation kernels obtained.
- Asymptotic properties of Painlevé functions studied in the context of random matrix theory.

## Abstract

We consider the Gaussian unitary ensemble perturbed by a Fisher-Hartwig singularity simultaneously of both root type and jump type. In the critical regime where the singularity approaches the soft edge, namely, the edge of the support of the equilibrium measure for the Gaussian weight, the asymptotics of the Hankel determinant and the recurrence coefficients, for the orthogonal polynomials associated with the perturbed Gaussian weight, are obtained and expressed in terms of a family of smooth solutions to the Painlev\'{e} XXXIV equation and the $\sigma$-form of the Painlev\'{e} II equation. In addition, we further obtain the double scaling limit of the distribution of the largest eigenvalue in a thinning procedure of the conditioning Gaussian unitary ensemble, and the double scaling limit of the correlation kernel for the critical perturbed Gaussian unitary ensemble. The asymptotic properties of the Painlev\'{e} XXXIV functions and the $\sigma$-form of the Painlev\'{e} II equation are also studied.