Critical edge statistics for deformed GinUEs
Dang-Zheng Liu, Lu Zhang
TL;DR
This work identifies the complete edge-statistics dichotomy for the deformed complex Ginibre ensemble: standard GinUE edge statistics at regular edge points and a novel, Pearcey-type critical edge statistics at critical boundary points. The authors develop a intricate integral-representation framework, reduce the problem via translation, translation-invariant symmetries, and concentration arguments, and implement a seven-step Taylor expansion alongside determinant expansions to isolate the leading behavior. The main achievement is a precise description of the critical-edge $n$-point correlations in terms of a matrix integral $I_n(\hat Z)$, combined with explicit exponential and determinant prefactors, providing a non-Hermitian analogue of Pearcey universality and suggesting a third universal edge class in non-Hermitian random matrix theory. The results illuminate the delicate interplay between spectral geometry of the perturbation $X_0$, the Brown measure boundary behavior, and non-Hermitian local statistics, and pave the way for further exploration of universal edge phenomena beyond the Ginibre family.
Abstract
For the complex Ginibre ensemble subjected to an additive perturbation by a deterministic normal matrix $X_0$, we establish that under specific spectral conditions on $X_0$, only two distinct types of local spectral statistics emerge at the spectral edge: GinUE statistics and critical statistics, which respectively correspond to regular and quadratically vanishing spectral points. The critical statistics, as a non-Hermitian analogue of Pearcey statistics in random matrix theory, describes a novel point process on the complex plane. This identifies the third (and likely final) universal statistics in non-Hermitian random matrix theory, after the established GinUE bulk and edge universality classes, and represents the primary achievement of this paper.
