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Coalescence in Critical and Subcritical Galton-Watson Branching Processes

Published online by Cambridge University Press:  04 February 2016

K. B. Athreya*
Affiliation:
Iowa State University
*
Postal address: Departments of Mathematics and Statistics, Iowa State University, Ames, Iowa, 50011, USA. Email address: kba@iastate.edu
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Abstract

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In a Galton-Watson branching process that is not extinct by the nth generation and has at least two individuals, pick two individuals at random by simple random sampling without replacement. Trace their lines of descent back in time till they meet. Call that generation Xn a pairwise coalescence time. Similarly, let Yn denote the coalescence time for the whole population of the nth generation conditioned on the event that it is not extinct. In this paper the distributions of Xn and Yn, and their limit behaviors as n → ∞ are discussed for both the critical and subcritical cases.

Type
Research Article
Copyright
© Applied Probability Trust 

References

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