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Asymptotic local lower deviations of strictly supercritical branching process in a random environment with geometric distributions of descendants

  • K. Yu. Denisov EMAIL logo
Published/Copyright: August 9, 2024

Abstract

We consider local probabilities of lower deviations for branching process Zn = Xn,1 + ⋯ + Xn,Zn−1 in random environment η. We assume that η is a sequence of independent identically distributed variables and for fixed η the variables Xi,j are independent and have geometric distributions. We suppose that steps ξi of the associated random walk Sn = ξ1 + ⋯ + ξn has positive mean and satisfies left-side Cramér condition: E exp(hξi) < ∞ if h < h < 0 for some h < − 1. Under these assumptions we find the asymptotic of the local probabilities P(Zn = ⌊exp(θn)⌋), n → ∞, for θ ∈ (max(m, 0); m(− 1)) and for θ in a neighbourhood of m(− 1), where m and m(− 1) are some constants.


Originally published in Diskretnaya Matematika (2022) 34, №4, 14–27 (in Russian).


Funding statement: This work was supported by the Russian Science Foundation under grant №19-11-00111, https://rscf.ru/project/19-11-00111/.

References

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Received: 2022-05-29
Published Online: 2024-08-09
Published in Print: 2024-08-27

© 2024 Walter de Gruyter GmbH, Berlin/Boston

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