{ "id": "1609.07909", "version": "v1", "published": "2016-09-26T10:07:16.000Z", "updated": "2016-09-26T10:07:16.000Z", "title": "Pickands' constant at first order in an expansion around Brownian motion", "authors": [ "Mathieu Delorme", "Alberto Rosso", "Kay Jörg Wiese" ], "comment": "13 pages, 3 figures", "categories": [ "cond-mat.stat-mech", "math-ph", "math.MP" ], "abstract": "In the theory of extreme values of Gaussian processes, many results are expressed in terms of the Pickands constant $\\mathcal{H}_{\\alpha}$. This constant depends on the local self-similarity exponent $\\alpha$ of the process, i.e. locally it is a fractional Brownian motion (fBm) of Hurst index $H=\\alpha/2$. Despite its importance, only two values of the Pickands constant are known: ${\\cal H}_1 =1$ and ${\\cal H}_2=1/\\sqrt{\\pi}$. Here, we extend the recent perturbative approach to fBm to include drift terms. This allows us to investigate the Pickands constant $\\mathcal{H}_{\\alpha}$ around standard Brownian motion ($\\alpha =1$) and to derive the new exact result $\\mathcal{H}_{\\alpha}=1 - (\\alpha-1) \\gamma_{\\rm E} + \\mathcal{O}\\!\\left( \\alpha-1\\right)^{2}$.", "revisions": [ { "version": "v1", "updated": "2016-09-26T10:07:16.000Z" } ], "analyses": { "keywords": [ "first order", "pickands constant", "standard brownian motion", "local self-similarity exponent", "fractional brownian motion" ], "note": { "typesetting": "TeX", "pages": 13, "language": "en", "license": "arXiv", "status": "editable" } } }