Phase transition in limiting distributions of coherence of high-dimensional random matrices

  • Authors:
  • T. Tony Cai;Tiefeng Jiang

  • Affiliations:
  • Statistics Department, The Wharton School, University of Pennsylvania, Philadelphia, PA 19104, United States;School of Statistics, University of Minnesota, 224 Church Street, MN 55455, United States

  • Venue:
  • Journal of Multivariate Analysis
  • Year:
  • 2012

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Abstract

The coherence of a random matrix, which is defined to be the largest magnitude of the Pearson correlation coefficients between the columns of the random matrix, is an important quantity for a wide range of applications including high-dimensional statistics and signal processing. Inspired by these applications, this paper studies the limiting laws of the coherence of nxp random matrices for a full range of the dimension p with a special focus on the ultra high-dimensional setting. Assuming the columns of the random matrix are independent random vectors with a common spherical distribution, we give a complete characterization of the behavior of the limiting distributions of the coherence. More specifically, the limiting distributions of the coherence are derived separately for three regimes: 1nlogp-0, 1nlogp-@b@?(0,~), and 1nlogp-~. The results show that the limiting behavior of the coherence differs significantly in different regimes and exhibits interesting phase transition phenomena as the dimension p grows as a function of n. Applications to statistics and compressed sensing in the ultra high-dimensional setting are also discussed.