Anisotropic local laws for random matrices


Loading...

Date

2017-10

Publication Type

Journal Article

ETH Bibliography

yes

Citations

Altmetric

Data

Abstract

We develop a new method for deriving local laws for a large class of random matrices. It is applicable to many matrix models built from sums and products of deterministic or independent random matrices. In particular, it may be used to obtain local laws for matrix ensembles that are anisotropic in the sense that their resolvents are well approximated by deterministic matrices that are not multiples of the identity. For definiteness, we present the method for sample covariance matrices of the form , where T is deterministic and X is random with independent entries. We prove that with high probability the resolvent of Q is close to a deterministic matrix, with an optimal error bound and down to optimal spectral scales. As an application, we prove the edge universality of Q by establishing the Tracy–Widom–Airy statistics of the eigenvalues of Q near the soft edges. This result applies in the single-cut and multi-cut cases. Further applications include the distribution of the eigenvectors and an analysis of the outliers and BBP-type phase transitions in finite-rank deformations; they will appear elsewhere. We also apply our method to Wigner matrices whose entries have arbitrary expectation, i.e. we consider W + A where W is a Wigner matrix and A a Hermitian deterministic matrix. We prove the anisotropic local law for W + A and use it to establish edge universality.

Publication status

published

Editor

Book title

Volume

169 (1)

Pages / Article No.

257 - 352

Publisher

Springer

Event

Edition / version

Methods

Software

Geographic location

Date collected

Date created

Subject

Organisational unit

Notes

It was possible to publish this article open access thanks to a Swiss National Licence with the publisher.

Funding

144662 - Spectral and eigenvector statistics of large random matrices (SNF)

Related publications and datasets