In this paper we provide sharp bounds on the $L_p$-norms of randomly
stopped $U$-statistics. These bounds consist mainly of decoupling inequalities
designed to reduce the level of dependence between the $U$-statistics and the
stopping time involved. We apply our results to obtain Wald’s equation
for $U$-statistics, moment convergence theorems and asymptotic expansions for
the moments of randomly stopped $U$-statistics. The proofs are based on
decoupling inequalities, symmetrization techniques, the use of subsequences and
induction arguments.
@article{1023481120,
author = {de la Pe\~na, Victor H. and Lai, Tze Leung},
title = {Moments of randomly stopped $U$-statistics},
journal = {Ann. Probab.},
volume = {25},
number = {4},
year = {1997},
pages = { 2055-2081},
language = {en},
url = {http://dml.mathdoc.fr/item/1023481120}
}
de la Peña, Victor H.; Lai, Tze Leung. Moments of randomly stopped $U$-statistics. Ann. Probab., Tome 25 (1997) no. 4, pp. 2055-2081. http://gdmltest.u-ga.fr/item/1023481120/