{ "id": "1608.02440", "version": "v1", "published": "2016-08-08T14:05:05.000Z", "updated": "2016-08-08T14:05:05.000Z", "title": "A branching random walk among disasters", "authors": [ "Nina Gantert", "Stefan Junk" ], "categories": [ "math.PR" ], "abstract": "We consider a branching random walk in a random space-time environment of disasters where each particle is killed when meeting a disaster. This extends the model of the \"random walk in a disastrous random environment\" introduced by [6]. We obtain a criterion for positive survival probability, see Theorem 1. The proofs for the subcritical and the supercritical cases follow standard arguments, which involve moment methods and a comparison with an embedded branching process with i.i.d. offspring distributions. The proof of almost sure extinction in the critical case is more difficult and uses the techniques from [4]. We also show that, in the case of survival, the number of particles grows exponentially fast.", "revisions": [ { "version": "v1", "updated": "2016-08-08T14:05:05.000Z" } ], "analyses": { "subjects": [ "60K37", "60J80", "82D60" ], "keywords": [ "branching random walk", "random space-time environment", "particles grows exponentially fast", "disastrous random environment", "positive survival probability" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }