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JOURNALS // Diskretnaya Matematika // Archive

Diskr. Mat., 2021 Volume 33, Issue 4, Pages 19–31 (Mi dm1664)

This article is cited in 1 paper

Asymptotic local probabilities of large deviations for branching process in random environment with geometric distribution of descendants

K. Yu. Denisov

Steklov Mathematical Institute of Russian Academy of Sciences, Moscow

Abstract: We consider the branching process $Z_{n} = X_{n, 1} + \dotsb + X_{n, Z_{n-1}}$ in random environments $\boldsymbol\eta$, where $\boldsymbol\eta$ is a sequence of independent identically distributed variables and for fixed $\boldsymbol\eta$ the random variables $X_{i,j}$ are independent and have the geometric distribution. We suppose that the associated random walk $S_n = \xi_1 + \dotsb + \xi_n$ has positive mean $\mu$ and satisfies the right-hand Cramer's condition ${\mathbf E}\exp(h\xi_i) < \infty$ for $0<h<h^{+}$ and some $h^{+}$. Under these assumptions, we find the asymptotic representation for local probabilities ${\mathbf P}\left( Z_n = \lfloor\exp\left(\theta n\right)\rfloor \right)$ for $\theta \in [\theta_1,\theta_2] \subset (\mu;\mu^+)$ and some $\mu^+$.

Keywords: branching processes, random environments, random walks, Cramer's condition, large deviations, local theorems.

UDC: 519.218.27

Received: 20.04.2021

DOI: 10.4213/dm1664


 English version:
Discrete Mathematics and Applications, 2023, 33:2, 77–86


© Steklov Math. Inst. of RAS, 2025