On Largest Offspring in a Critical Branching Process with Finite Variance

2013 ◽  
Vol 50 (03) ◽  
pp. 791-800 ◽  
Author(s):  
Jean Bertoin

Continuing the work in Bertoin (2011) we study the distribution of the maximal number X * k of offspring amongst all individuals in a critical Galton‒Watson process started with k ancestors, treating the case when the reproduction law has a regularly varying tail F̅ with index −α for α > 2 (and, hence, finite variance). We show that X * k suitably normalized converges in distribution to a Fréchet law with shape parameter α/2; this contrasts sharply with the case 1< α<2 when the variance is infinite. More generally, we obtain a weak limit theorem for the offspring sequence ranked in decreasing order, in terms of atoms of a certain doubly stochastic Poisson measure.

2013 ◽  
Vol 50 (3) ◽  
pp. 791-800 ◽  
Author(s):  
Jean Bertoin

Continuing the work in Bertoin (2011) we study the distribution of the maximal number X*k of offspring amongst all individuals in a critical Galton‒Watson process started with k ancestors, treating the case when the reproduction law has a regularly varying tail F̅ with index −α for α > 2 (and, hence, finite variance). We show that X*k suitably normalized converges in distribution to a Fréchet law with shape parameter α/2; this contrasts sharply with the case 1< α<2 when the variance is infinite. More generally, we obtain a weak limit theorem for the offspring sequence ranked in decreasing order, in terms of atoms of a certain doubly stochastic Poisson measure.


2011 ◽  
Vol 48 (02) ◽  
pp. 576-582 ◽  
Author(s):  
Jean Bertoin

We investigate the maximal number M k of offspring amongst all individuals in a critical Galton-Watson process started with k ancestors. We show that when the reproduction law has a regularly varying tail with index -α for 1 &lt; α &lt; 2, then k -1 M k converges in distribution to a Frechet law with shape parameter 1 and scale parameter depending only on α.


2011 ◽  
Vol 48 (2) ◽  
pp. 576-582 ◽  
Author(s):  
Jean Bertoin

We investigate the maximal number Mk of offspring amongst all individuals in a critical Galton-Watson process started with k ancestors. We show that when the reproduction law has a regularly varying tail with index -α for 1 < α < 2, then k-1Mk converges in distribution to a Frechet law with shape parameter 1 and scale parameter depending only on α.


2014 ◽  
Vol 2014 ◽  
pp. 1-4
Author(s):  
Zhenlong Gao ◽  
Yanhua Zhang

We extend Donsker’s theorem and the central limit theorem of classical Galton-Watson process to the Galton-Watson processes in varying environment.


2009 ◽  
Vol 46 (2) ◽  
pp. 453-462 ◽  
Author(s):  
Yuqiang Li

In this paper we prove that a sequence of scaled generalized Jiřina processes can converge weakly to a nonlinear diffusion process with Lévy jumps under certain conditions.


2007 ◽  
Vol 44 (03) ◽  
pp. 753-769 ◽  
Author(s):  
S. V. Nagaev ◽  
V. Wachtel

In this paper we prove a conditional limit theorem for a critical Galton-Watson branching process {Z n ; n ≥ 0} with offspring generating function s + (1 − s)L((1 − s)−1), where L(x) is slowly varying. In contrast to a well-known theorem of Slack (1968), (1972) we use a functional normalization, which gives an exponential limit. We also give an alternative proof of Sze's (1976) result on the asymptotic behavior of the nonextinction probability.


2018 ◽  
Vol 17 (9) ◽  
Author(s):  
Masaya Maeda ◽  
Hironobu Sasaki ◽  
Etsuo Segawa ◽  
Akito Suzuki ◽  
Kanako Suzuki

1978 ◽  
Vol 15 (02) ◽  
pp. 225-234 ◽  
Author(s):  
Harry Cohn ◽  
Anthony G. Pakes

It is known that for a Bienaymé– Galton–Watson process {Zn } whose mean m satisfies 1 &lt; m &lt; ∞, the limiting random variable in the strong limit theorem can be represented as a random sum of i.i.d. random variables and hence that convergence rate results follow from a random sum central limit theorem. This paper develops an analogous theory for the case m = ∞ which replaces ‘sum' by ‘maximum'. In particular we obtain convergence rate results involving a limiting extreme value distribution. An associated estimation problem is considered.


2009 ◽  
Vol 46 (02) ◽  
pp. 453-462 ◽  
Author(s):  
Yuqiang Li

In this paper we prove that a sequence of scaled generalized Jiřina processes can converge weakly to a nonlinear diffusion process with Lévy jumps under certain conditions.


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