English

Asymptotic behavior of random determinants in the Laguerre, Gram and Jacobi ensembles

Probability 2008-01-30 v4

Abstract

We consider properties of determinants of some random symmetric matrices issued from multivariate statistics: Wishart/Laguerre ensemble (sample covariance matrices), Uniform Gram ensemble (sample correlation matrices) and Jacobi ensemble (MANOVA). If nn is the size of the sample, rnr\leq n the number of variates and Xn,rX_{n,r} such a matrix, a generalization of the Bartlett-type theorems gives a decomposition of detXn,r\det X_{n,r} into a product of rr independent gamma or beta random variables. For nn fixed, we study the evolution as rr grows, and then take the limit of large rr and nn with r/n=t1r/n = t \leq 1. We derive limit theorems for the sequence of {\it processes with independent increments} {n1logdetXn,nt,t[0,T]}n\{n^{-1} \log \det X_{n, \lfloor nt\rfloor}, t \in [0, T]\}_n for T1T \leq 1.. Since the logarithm of the determinant is a linear statistic of the empirical spectral distribution, we connect the results for marginals (fixed tt) with those obtained by the spectral method. Actually, all the results hold true for β\beta models, if we define the determinant as the product of charges.

Keywords

Cite

@article{arxiv.math/0607767,
  title  = {Asymptotic behavior of random determinants in the Laguerre, Gram and Jacobi ensembles},
  author = {Alain Rouault},
  journal= {arXiv preprint arXiv:math/0607767},
  year   = {2008}
}

Comments

51 pages ; it replaces and extends arXiv:math/0607767 and arXiv:math/0509021 Third version: corrected constants in Theorem 3.1