{ "id": "1811.05495", "version": "v1", "published": "2018-11-13T19:02:47.000Z", "updated": "2018-11-13T19:02:47.000Z", "title": "Phase transition for the frog model on biregular trees", "authors": [ "Elcio Lebensztayn", "Jaime Utria" ], "categories": [ "math.PR" ], "abstract": "We study the frog model with death on the biregular tree $\\mathbb{T}_{d_1,d_2}$. Initially, there is a random number of awake and sleeping particles located on the vertices of the tree. Each awake particle moves as a discrete-time independent simple random walk on $\\mathbb{T}_{d_1,d_2}$ and has a probability of death $(1-p)$ before each step. When an awake particle visits a vertex which has not been visited previously, the sleeping particles placed there are awakened. We prove that this model undergoes a phase transition: for values of $p$ below a critical probability $p_c$, the system dies out almost surely, and for $p > p_c$, the system survives with positive probability. We establish explicit bounds for $p_c$ in the case of random initial configuration. For the model starting with one particle per vertex, the critical probability satisfies $p_c(\\mathbb{T}_{d_1,d_2}) = 1/2 + \\Theta(1/d_1+1/d_2)$ as $d_1, d_2 \\to \\infty$.", "revisions": [ { "version": "v1", "updated": "2018-11-13T19:02:47.000Z" } ], "analyses": { "keywords": [ "frog model", "phase transition", "biregular tree", "discrete-time independent simple random walk", "probability" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }