##Statistics Seminar##\\ Department of Mathematical Sciences
^ **DATE:**|Thursday, March 3, 2022 |
^ **TIME:**|1:15pm -- 2:15pm |
^ **LOCATION:**|Zoom meeting |
^ **SPEAKER:**|Geran Zhao, Binghamton University |
^ **TITLE:**|Asymptotic distribution of high-dimensional distance correlation inference |
\\
**Abstract**
Distance correlation has become an increasingly popular tool
for detecting the nonlinear dependence between a pair of potentially high-dimensional
random vectors. Most existing works have explored its asymptotic distributions under the null hypothesis of independence between the two random
vectors when only the sample size or the dimensionality diverges. Yet its
asymptotic null distribution for the more realistic setting when both sample size and dimensionality diverge in the full range remains largely underdeveloped. In this paper, we fill such a gap and develop central limit
theorems and associated rates of convergence for a rescaled test statistic based on
the bias-corrected distance correlation in high dimensions under some mild regularity conditions and the null hypothesis. Our new theoretical results
reveal an interesting phenomenon of blessing of dimensionality for high-dimensional distance correlation inference in the sense that the accuracy of normal approximation can increase with dimensionality. Moreover, we provide a general theory on the power analysis under the alternative hypothesis of depen-
dence, and further justify the capability of the rescaled distance
correlation in capturing the pure nonlinear dependency under moderately high dimensionality for a certain type of alternative hypothesis. The theoretical results
and finite-sample performance of the rescaled statistic are illustrated with
several
simulation examples and a blockchain application.