2022/12/25 by Shuxiong Zhang, Zhang, Shuxiong
Mathematics · Physics and Astronomy · #Stochastic processes and statistical mechanics #Theoretical and Computational Physics #Markov Chains and Monte Carlo Methods
paper · pdf · doi:10.48550/arxiv.2212.12835
Let \Zn\n≥ 0 be a d-dimensional supercritical branching random walk started from the origin. Write Zn(S) for the number of particles located in a set S⊂ℝd at time n. Denote by Rn:=inf\ρ:Zi(\|x|≥ ρ\)=0,∀~0≤ i≤ n\ the range of \Zn\n≥ 0 before time n. In this work, we show that under some mild conditions Rn/n converges in probability to some positive constant x^* as n→∞. Furthermore, we study its corresponding lower and upper deviation probabilities, i.e. the decay rates of ℙ(Rn≤ xn)~for~x∈(0,x^*);~ℙ(Rn≥ xn) ~for~ x∈(x^*,∞) as n→∞. As a by-product, we confirm a conjecture of Engländer \citeEnglander04.