On the survival of a class of subcritical branching processes in random environment

Let $Z_{n}$ be the number of individuals in a subcritical BPRE evolving in the environment generated by iid probability distributions. Let $X$ be the logarithm of the expected offspring size per individual given the environment. Assuming that the density of $X$ has the form $$p_{X}(x)=x^{-\beta -1}l_{0}(x)e^{-\rho x}$$ for some $\beta >2,$ a slowly varying function $l_{0}(x)$ and $\rho \in \left( 0,1\right),$ we find the asymptotic survival probability and prove a Yaglom type conditional limit theorem for the process. The survival probability decreases exponentially with an additional polynomial term related to the tail of $X$. The proof relies on a fine study of a random walk (with negative drift and heavy tails) conditioned to stay positive until time $n$ and to have a small positive value at time $n$, with $n$ tending to infinity.

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Source https://hal.science/hal-00844584
Author Bansaye, Vincent, Vatutin, Vladimir
Maintainer CCSD
Last Updated May 7, 2026, 17:50 (UTC)
Created May 7, 2026, 17:50 (UTC)
Identifier hal-00844584
Language en
Rights https://about.hal.science/hal-authorisation-v1/
contributor Centre de Mathématiques Appliquées de l'Ecole polytechnique (CMAP) ; Institut National de Recherche en Informatique et en Automatique (Inria)-École polytechnique (X) ; Institut Polytechnique de Paris (IP Paris)-Institut Polytechnique de Paris (IP Paris)-Centre National de la Recherche Scientifique (CNRS)
creator Bansaye, Vincent
date 2013-12-19T00:00:00
harvest_object_id a000f22e-8090-4097-b95a-5227cbbe2dc4
harvest_source_id 3374d638-d20b-4672-ba96-a23232d55657
harvest_source_title test moissonnage SELUNE
metadata_modified 2025-09-04T00:00:00
relation info:eu-repo/semantics/altIdentifier/arxiv/1307.3963
set_spec type:REPORT