2021/02/05 by Zongming Ma, Fan Yang, Ma, Zongming +1 · 1 citation
Mathematics · #Advanced Algebra and Geometry #FOS: Mathematics #Geometry and complex manifolds #Probability (math.PR) #Random Matrices and Applications
paper · pdf · doi:10.48550/arxiv.2102.03297
openalex publication_date 2021/02/05 · openalex created_date 2021/02/15 · openalex updated_date 2026/07/28
Consider two random vectors \widetilde\mathbf x ∈ \mathbb Rp and \widetilde\mathbf y ∈ \mathbb Rq of the forms \widetilde\mathbf x=A\mathbf z+\mathbf C11/2\mathbf x and \widetilde\mathbf y=B\mathbf z+\mathbf C21/2\mathbf y, where \mathbf x∈ \mathbb Rp, \mathbf y∈ \mathbb Rq and \mathbf z∈ \mathbb Rr are independent vectors with i.i.d. entries of mean 0 and variance 1, \mathbf C1 and \mathbf C2 are p × p and q× q deterministic covariance matrices, and A and B are p× r and q× r deterministic matrices. With n independent observations of (\widetilde\mathbf x,\widetilde\mathbf y), we study the sample canonical correlations between \widetilde\mathbf x and \widetilde\mathbf y. We consider the high-dimensional setting with finite rank correlations. Let t1≥ t2 ≥ ⋯≥ tr be the squares of the nontrivial population canonical correlation coefficients, and let \widetildeλ1 ≥\widetildeλ2≥⋯≥\widetildeλp\wedge q be the squares of the sample canonical correlation coefficients. If the entries of \mathbf x, \mathbf y and \mathbf z are i.i.d. Gaussian, then the following dichotomy has been shown in [7] for a fixed threshold tc ∈(0, 1): for 1≤ i ≤ r, if ti < tc, then \widetildeλi converges to the right-edge λ+ of the limiting eigenvalue spectrum of the sample canonical correlation matrix; if ti>tc, then \widetildeλi converges to a deterministic limit θi ∈ (λ+,1) determined by ti. In this paper, we prove that these results hold universally under the sharp fourth moment conditions on the entries of \mathbf x and \mathbf y. Moreover, we prove the results in full generality, in the sense that they also hold for near-degenerate ti's and for ti's that are close to the threshold tc.