{ "id": "2001.12008", "version": "v1", "published": "2020-01-31T18:58:38.000Z", "updated": "2020-01-31T18:58:38.000Z", "title": "Conformal Skorokhod Embeddings of the uniform distribution and related extremal problems", "authors": [ "Phanuel Mariano", "Hugo Panzo" ], "comment": "11 pages", "categories": [ "math.PR" ], "abstract": "Let $\\mu$ be a probability distribution with zero mean and finite variance. The conformal Skorokhod embedding problem (CSEP) asks for a simply connected domain $D\\subset\\mathbb{C}$ such that the real part of standard complex Brownian motion at its first exit time from $D$ has distribution $\\mu$ with the exit time having finite mean. The CSEP was first posed and solved by Gross (2019) where the author gives an explicit construction of a solution. In this paper we give an example of a simply connected domain $\\mathbb{U}$ that embeds the uniform distribution on $[-1,1]$ which differs from Gross' solution and possesses a certain extremal property. More precisely, if $D$ is any solution of the CSEP for the uniform distribution on $[-1,1]$, then the principal Dirichlet eigenvalue of $D$ is at least that of $\\mathbb{U}$. We also give general upper and lower bounds on the principal Dirichlet eigenvalue of a solution to the CSEP for any $\\mu$. The proofs rely on a spectral upper bound of the torsion function as well as a precise relation between the widths of the orthogonal projections of a simply connected domain and the support of its harmonic measure which is developed in the paper.", "revisions": [ { "version": "v1", "updated": "2020-01-31T18:58:38.000Z" } ], "analyses": { "keywords": [ "uniform distribution", "related extremal problems", "simply connected domain", "principal dirichlet eigenvalue", "exit time" ], "note": { "typesetting": "TeX", "pages": 11, "language": "en", "license": "arXiv", "status": "editable" } } }