Hostname: page-component-848d4c4894-wzw2p Total loading time: 0 Render date: 2024-05-14T18:39:36.758Z Has data issue: false hasContentIssue false

Branching random walk in varying environments

Published online by Cambridge University Press:  01 July 2016

C. F. Klebaner*
Affiliation:
University of Melbourne
*
Postal address: Department of Statistics, Richard Berry Building, University of Melbourne, Parkville, VIC3052, Australia.

Abstract

The branching random walk model is generalized towards generation-dependent displacement and reproduction distributions. Asymptotic theory of branching random walk in varying environments from the L2 point of view is given. If Zn(x) is the number of nth-generation particles to the left of x, then under appropriate conditions for suitably chosen xn, Zn (xn)/Zn (+∞) converges in L2 completely to a limiting distribution. Sufficient conditions for almost sure convergence are given. As a corollary an analogue of the central limit theorem for the proportion of particles of the nth generation in time interval In in the age-dependent Crump–Mode–Jagers process is obtained.

Type
Research Article
Copyright
Copyright © Applied Probability Trust 1982 

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

[1] Agresti, A. (1975) On the extinction times of varying and random environment branching processes. J. Appl. Prob. 12, 3946.Google Scholar
[2] Asmussen, S. and Kaplan, N. (1976) Branching random walks I. Stoch. Proc. Appl. 4, 113.Google Scholar
[3] Athreya, K. B. and Ney, R. (1971) Limit theorems for the mean of branching random walks. Proc. 6th Prague Conf. Information Theory. 6372.Google Scholar
[4] Biggins, J. D. (1977) Martingale convergence in the branching random walk. J. Appl. Prob. 14, 2537.CrossRefGoogle Scholar
[5] Biggins, J. D. (1978) The asymptotic shape of the branching random walk. Adv. Appl. Prob. 10, 6284.Google Scholar
[6] Biggins, J. D. (1979) Growth rates in the branching random walk. Z. Wahrscheinlichkeitsth. 48, 1734.Google Scholar
[7] Bramson, M. D. (1978) Minimal displacement of branching random walk. Z. Wahrscheinlichkeitsth. 45, 89108.CrossRefGoogle Scholar
[8] CraméR, H. (1963) Random Variables and Probability Distributions. Cambridge University Press, London.Google Scholar
[9] Durrett, R. (1979) Maxima of branching random walks vs. independent random walks. Stoch. Proc. Appl. 9, 117136.Google Scholar
[10] Edler, L. (1978) Strict supercritical generation-dependent Crump-Mode-Jagers branching processes. Adv. Appl. Prob. 10, 744763.CrossRefGoogle Scholar
[11] Fearn, D. H. (1972) Galton-Weston processes with generation dependence. Proc. 6th Berkeley Symp. Math. Statist. Prob. 4, 158172.Google Scholar
[12] Fearn, D. H. (1976) Supercritical age-dependent branching processes with generation dependence. Ann. Prob. 4, 2737.Google Scholar
[13] Fildes, R. (1972) An age-dependent branching process with variable lifetime distribution. Adv. Appl. Prob. 4, 453474.Google Scholar
[14] Fildes, R. (1974) An age-dependent branching process with variable lifetime distribution: The generation size. Adv. Appl. Prob. 6, 291308.CrossRefGoogle Scholar
[15] Gnedenko, B. V. and Kolmogorov, A. N. (1954) Limit Distributions for the Sums of Independent Random Variables. Addison-Wesley, Reading, MA.Google Scholar
[16] Goettge, R. T. (1975) Limit theorem for the supercritical Galton-Watson process in varying environment. Math. Biosci. 28, 171190.Google Scholar
[17] Harris, T. E. (1963) The Theory of Branching Processes. Springer-Verlag, Berlin.CrossRefGoogle Scholar
[18] Jagers, P. (1969) A general stochastic model for population development. Skand. Aktuarietidskr. 52, 84103.Google Scholar
[19] Joffe, A. and Moncayo, A. R. (1973) Asymptotic theorems for sums of independent random variables defined on a tree. Bull. Amer. Math. Soc. 79, 12201222.CrossRefGoogle Scholar
[20] Joffe, A. and Moncayo, A. R. (1973) Random variables, trees and branching random walks. J. Adv. Math. 10, 401416.Google Scholar
[21] Kaplan, N. and Asmussen, S. (1976) Branching random walks II. Stoch. Proc. Appl. 4, 1531.Google Scholar
[22] Ney, P. (1964) Generalized branching processes I. Existence and uniqueness theorems. Illinois J. Math. 8, 316331.Google Scholar
[23] Ney, P. (1964) Generalized branching processes II. Asymptotic theory. Illinois J. Math. 8, 331350.Google Scholar
[24] Ney, P. E. (1965) The convergence of a random distribution function associated with a branching process. J. Math. Anal. Appl. 12, 316327.CrossRefGoogle Scholar
[25] Samuels, M. L. (1971) Distribution of the branching process population among generations. J. Appl. Prob. 8, 655667.Google Scholar
[26] Stam, A. J. (1966) On the conjecture of Harris. Z. Wahrscheinlichkeitsth. 5, 202206.CrossRefGoogle Scholar