{ "id": "2312.01952", "version": "v1", "published": "2023-12-04T15:11:03.000Z", "updated": "2023-12-04T15:11:03.000Z", "title": "Fragmentation processes and the convex hull of the Brownian motion in a disk", "authors": [ "Bénédicte Haas", "Bastien Mallein" ], "categories": [ "math.PR" ], "abstract": "Motivated by the study of the convex hull of the trajectory of a Brownian motion in the unit disk reflected orthogonally at its boundary, we study inhomogeneous fragmentation processes in which particles of mass $m \\in (0,1)$ split at a rate proportional to $|\\log m|^{-1}$. These processes do not belong to the well-studied family of self-similar fragmentation processes. Our main results characterize the Laplace transform of the typical fragment of such a process, at any time, and its large time behavior. We connect this asymptotic behavior to the prediction obtained by physicists in \\cite{DBBM22} for the growth of the perimeter of the convex hull of a Brownian motion in the disc reflected at its boundary. We also describe the large time asymptotic behavior of the whole fragmentation process. In order to implement our results, we make a detailed study of a time-changed subordinator, which may be of independent interest.", "revisions": [ { "version": "v1", "updated": "2023-12-04T15:11:03.000Z" } ], "analyses": { "subjects": [ "60J25", "60D05", "60G51", "60J80" ], "keywords": [ "convex hull", "brownian motion", "large time asymptotic behavior", "self-similar fragmentation processes", "large time behavior" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }