Marchenko–Pastur law with relaxed independence conditions
Abstract
We prove the Marchenko–Pastur law for the eigenvalues of [Formula: see text] sample covariance matrices in two new situations where the data does not have independent coordinates. In the first scenario — the block-independent model — the [Formula: see text] coordinates of the data are partitioned into blocks in such a way that the entries in different blocks are independent, but the entries from the same block may be dependent. In the second scenario — the random tensor model — the data is the homogeneous random tensor of order [Formula: see text], i.e. the coordinates of the data are all [Formula: see text] different products of [Formula: see text] variables chosen from a set of [Formula: see text] independent random variables. We show that Marchenko–Pastur law holds for the block-independent model as long as the size of the largest block is [Formula: see text], and for the random tensor model as long as [Formula: see text]. Our main technical tools are new concentration inequalities for quadratic forms in random variables with block-independent coordinates, and for random tensors.
Document Details
- Document Type
- Pub Defense Publication
- Publication Date
- Feb 19, 2021
- Source ID
- 10.1142/s2010326321500404
Entities
People
- Hongkai Zhao
- Jennifer S. Bryson
- Roman Vershynin
Organizations
- Duke University
- National Science Foundation
- United States Air Force
- University of California