{ "id": "0904.1167", "version": "v3", "published": "2009-04-07T15:21:43.000Z", "updated": "2010-09-29T15:33:52.000Z", "title": "Martingales and Rates of Presence in Homogeneous Fragmentations", "authors": [ "Nathalie Krell", "Alain Rouault" ], "comment": "In this version, we correct a misprint in Assumption A from the previous one", "categories": [ "math.PR" ], "abstract": "The main focus of this work is the asymptotic behavior of mass-conservative homogeneous fragmentations. Considering the logarithm of masses makes the situation reminiscent of branching random walks. The standard approach is to study {\\bf asymptotical} exponential rates. For fixed $v > 0$, either the number of fragments whose sizes at time $t$ are of order $\\e^{-vt}$ is exponentially growing with rate $C(v) > 0$, i.e. the rate is effective, or the probability of presence of such fragments is exponentially decreasing with rate $C(v) < 0$, for some concave function $C$. In a recent paper, N. Krell considered fragments whose sizes decrease at {\\bf exact} exponential rates, i.e. whose sizes are confined to be of order $\\e^{-vs}$ for every $s \\leq t$. In that setting, she characterized the effective rates. In the present paper we continue this analysis and focus on probabilities of presence, using the spine method and a suitable martingale.", "revisions": [ { "version": "v3", "updated": "2010-09-29T15:33:52.000Z" } ], "analyses": { "keywords": [ "homogeneous fragmentations", "martingale", "exponential rates", "standard approach", "main focus" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2009arXiv0904.1167K" } } }