Strong renewal theorems with infinite mean
Strong renewal theorems with infinite mean
复制标题
具有无限均值的强更新定理
DOI:
10.1090/s0002-9947-1970-0268976-9
复制
发表时间:
1970
影响因子:
1.3
通讯作者:
K. B. Erickson
中科院分区:
文献类型:
--
作者:
K. B. Ericksonc;K. B. Erickson
Let F be a nonarithmetic probability distribution on (0, oo) and suppose 1 —F(f) is regularly varying at oo with exponent a, 0<aál. Let U(t) = J, F"'(t) be the renewal function. In this paper we first derive various asymptotic expressions for the quantity U(t+h)— U(t) as t -* oo, h>0 fixed. Next we derive asymptotic relations for the convolution U*z(t), t —>■ oo, for a large class of integrable functions z. All of these asymptotic relations are expressed in terms of the truncated mean function m(t) = f0 [1 — F(x)] dx, t large, and appear as the natural extension of the classical strong renewal theorem for distributions with finite mean. Finally in the last sections of the paper we apply the special case a = l to derive some limit theorems for the distributions of certain waiting times associated with a renewal process. 1. Principal theorems. Let A be a probability measure concentrated on [0, oo)(2) and let U be the associated renewal measure defined for any measurable set / by (l.i) t/{/} = !>"•{/} 0 where Fn' denotes the «-fold convolution of F with itself (P°* is the probability measure concentrated at the origin). The series (1.1) converges to a finite number for every bounded I. (For this and other elementary properties of U see [3, VI. 6] ; for a probabilistic interpretation of U see §9 in this paper.) We write U(x) for U{[0, x]} and we shall henceforth ignore the distinction between U the measure and U the function. (This convention applies to other measures as well.) The main results of this paper deal primarily with the differences U(t+h) — U(t) for h>0 fixed, and t -*■ oo. The principal assumption is that Phas the form (1.2) \-F(t) = t~aL(t), t>0, Received by the editors October 4, 1969. A MS Subject Classifications. Primary 6070, 6020, 6030; Secondary 4042, 4252.