English

On minimal singular values of random matrices with correlated entries

Probability 2013-09-24 v1

Abstract

Let X\mathbf X be a random matrix whose pairs of entries XjkX_{jk} and XkjX_{kj} are correlated and vectors (Xjk,Xkj) (X_{jk},X_{kj}), for 1j<kn1\le j<k\le n, are mutually independent. Assume that the diagonal entries are independent from off-diagonal entries as well. We assume that EXjk=0\mathbb{E} X_{jk}=0, EXjk2=1\mathbb{E} X_{jk}^2=1, for any j,k=1,,nj,k=1,\ldots,n and EXjkXkj=ρ\mathbb{E} X_{jk}X_{kj}=\rho for 1j<kn1\le j<k\le n. Let Mn\mathbf M_n be a non-random n×nn\times n matrix with MnKnQ\|\mathbf M_n\|\le Kn^Q, for some positive constants K>0K>0 and Q0Q\ge 0. Let sn(X+Mn)s_n(\mathbf X+\mathbf M_n) denote the least singular value of the matrix X+Mn\mathbf X+\mathbf M_n. It is shown that there exist positive constants AA and BB depending on K,Q,ρK,Q,\rho only such that P(sn(X+Mn)nA)nB. \mathbb{P}(s_n(\mathbf X+\mathbf M_n)\le n^{-A})\le n^{-B}. As an application of this result we prove the elliptic law for this class of matrices with non identically distributed correlated entries.

Keywords

Cite

@article{arxiv.1309.5711,
  title  = {On minimal singular values of random matrices with correlated entries},
  author = {Friedrich Götze and Alexey Naumov and Alexander Tikhomirov},
  journal= {arXiv preprint arXiv:1309.5711},
  year   = {2013}
}

Comments

27 pages, 1 figure