Eigenstate Thermalization Hypothesis for Generalized Wigner Matrices

TL;DR

This paper extends the Eigenvector Thermalization hypothesis to generalized Wigner matrices with correlated entries, developing a system of self-consistent equations for multiresolvent traces to analyze their spectral properties.

Contribution

It introduces a novel approach to handle covariance-induced complexities by formulating a system of self-consistent equations for families of matrices.

Findings

Derived self-consistent equations for multiresolvent traces

Analyzed the spectral behavior of generalized Wigner matrices

Extended eigenvector thermalization results to correlated cases

Abstract

In this paper, we extend results of Eigenvector Thermalization to the case of generalized Wigner matrices. Analytically, the central quantity of interest here are multiresolvent traces, such as $\Lambda_A:= \frac{1}{N} \text{Tr }{ GAGA}$. In the case of Wigner matrices, as in \cite{cipolloni-erdos-schroder-2021}, one can form a self-consistent equation for a single $\Lambda_A$. There are multiple difficulties extending this logic to the case of general covariances. The correlation structure prevents us from deriving a self-consistent equation for a single matrix $A$; this is due to the introduction of new terms that are quite distinct from the form of $\Lambda_A$. We find a way around this by carefully splitting these new terms and writing them as sums of $\Lambda_B$, for matrices $B$ obtained by modifying $A$ using the covariance matrix. The result is a system of self-consistent equations relating families of deterministic matrices. Our main effort in this work is to derive and analyze this system of self-consistent equations.