Decorrelation estimates for random Schr\"odinger operators with non rank one perturbations

TL;DR

This paper establishes decorrelation estimates for random Schrödinger operators with finite-rank perturbations, demonstrating independence of eigenvalue statistics at different energies and implications for eigenvalue multiplicity.

Contribution

It extends decorrelation estimates to models with finite-rank perturbations and links these to eigenvalue independence and multiplicity bounds.

Findings

Eigenvalue statistics at energies separated by more than 4d are independent.

Eigenvalues follow a compound Poisson distribution with finite support Levy measure.

Eigenvalues in the localization region have multiplicity at most the perturbation rank.

Abstract

We prove decorrelation estimates for generalized lattice Anderson models on $Z^d$ constructed with finite-rank perturbations in the spirit of Klopp \cite{klopp}. These are applied to prove that the local eigenvalue statistics $\xi^\omega_{E}$ and $\xi^\omega_{E^\prime}$, associated with two energies $E$ and $E'$ satisfying $|E - E'| > 4d$, are independent. That is, if $I,J$ are two bounded intervals, the random variables $\xi^\omega_{E}(I)$ and $\xi^\omega_{E'}(J)$, are independent and distributed according to a compound Poisson distribution whose L\'evy measure has finite support. We also prove that the extended Minami estimate implies that the eigenvalues in the localization region have multiplicity at most the rank of the perturbation.