{ "id": "1312.6069", "version": "v2", "published": "2013-12-20T18:42:27.000Z", "updated": "2014-04-23T13:05:41.000Z", "title": "A fractional Brownian field indexed by $L^2$ and a varying Hurst parameter", "authors": [ "Alexandre Richard" ], "categories": [ "math.PR" ], "abstract": "Using structures of Abstract Wiener Spaces, we define a fractional Brownian field indexed by a product space $(0,1/2] \\times L^2(T,m)$, $(T,m)$ a separable measure space, where the first coordinate corresponds to the Hurst parameter of fractional Brownian motion. This field encompasses a large class of existing fractional Brownian processes, such as L\\'evy fractional Brownian motions and multiparameter fractional Brownian motions, and provides a setup for new ones. We prove that it has satisfactory incremental variance in both coordinates and derive certain continuity and H\\\"older regularity properties in relation with metric entropy. Also, a sharp estimate of the small ball probabilities is provided, generalizing a result on L\\'evy fractional Brownian motion. Then, we apply these general results to multiparameter and set-indexed processes, proving the existence of processes with prescribed local H\\\"older regularity on general indexing collections.", "revisions": [ { "version": "v2", "updated": "2014-04-23T13:05:41.000Z" } ], "analyses": { "keywords": [ "fractional brownian field", "varying hurst parameter", "levy fractional brownian motion", "multiparameter fractional brownian motions", "small ball probabilities" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2013arXiv1312.6069R" } } }