Limit theorems for sums of heavy-tailed variables with random dependent weights

被引:1
|
作者
Stoev, Stilian A.
Taqqu, Murad S.
机构
[1] Univ Michigan, Dept Stat, Ann Arbor, MI 48109 USA
[2] Boston Univ, Dept Math & Stat, Boston, MA 02215 USA
基金
美国国家科学基金会;
关键词
weighted sums; random weights; limit theorems; stable Levy motion; Skorohod topology; strong M-1-topology;
D O I
10.1007/s11009-006-9011-5
中图分类号
O21 [概率论与数理统计]; C8 [统计学];
学科分类号
020208 ; 070103 ; 0714 ;
摘要
Let U-j, j is an element of N be independent and identically distributed random variables with heavy- tailed distributions. Consider a sequence of random weights {W-j} j is an element of N, independent of {U-j} (j is an element of N) and focus on the weighted sums Sigma([nt])(j=1) W-j( U-j - mu), where mu involves a suitable centering. We establish sufficient conditions for these weighted sums to converge to non- trivial limit processes, as n -> infinity, when appropriately normalized. The convergence holds, for example, if {Wj} j. N is strictly stationary, dependent, and W-1 has lighter tails than U-1. In particular, the weights W-js can be strongly dependent. The limit processes are scale mixtures of stable Levy motions. We establish weak convergence in the Skorohod J(1)-topology. We also consider multivariate weights and show that they converge weakly in the strong Skorohod M-1- topology. The M-1-topology, while weaker than the J(1)-topology, is strong enough for the supremum and infimum functionals to be continuous.
引用
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页码:55 / 87
页数:33
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