{ "id": "2105.15060", "version": "v1", "published": "2021-05-31T15:46:44.000Z", "updated": "2021-05-31T15:46:44.000Z", "title": "Convex minorants and the fluctuation theory of Lévy processes", "authors": [ "Jorge Ignacio González Cázares", "Aleksandar Mijatović" ], "comment": "15 pages, 2 figures, short video on https://youtu.be/hEg4YmxOgXA", "categories": [ "math.PR" ], "abstract": "We establish a novel characterisation of the law of the convex minorant of any L\\'evy process. Our self-contained elementary proof is based on the analysis of piecewise linear convex functions and requires only very basic properties of L\\'evy processes. Our main result provides a new simple and self-contained approach to the fluctuation theory of L\\'evy processes, circumventing local time and excursion theory. Easy corollaries include classical theorems, such as Rogozin's regularity criterion, Spitzer's identities and the Wiener-Hopf factorisation, as well as a novel factorisation identity.", "revisions": [ { "version": "v1", "updated": "2021-05-31T15:46:44.000Z" } ], "analyses": { "subjects": [ "60G51" ], "keywords": [ "convex minorant", "fluctuation theory", "lévy processes", "levy process", "novel factorisation identity" ], "note": { "typesetting": "TeX", "pages": 15, "language": "en", "license": "arXiv", "status": "editable" } } }