{ "id": "1801.08008", "version": "v1", "published": "2018-01-24T14:53:29.000Z", "updated": "2018-01-24T14:53:29.000Z", "title": "Cones generated by random points on half-spheres and convex hulls of Poisson point processes", "authors": [ "Zakhar Kabluchko", "Alexander Marynych", "Daniel Temesvari", "Christoph Thaele" ], "categories": [ "math.PR", "math.MG" ], "abstract": "Let $U_1,U_2,\\ldots$ be random points sampled uniformly and independently from the $d$-dimensional upper half-sphere. We show that, as $n\\to\\infty$, the $f$-vector of the $(d+1)$-dimensional convex cone $C_n$ generated by $U_1,\\ldots,U_n$ weakly converges to a certain limiting random vector, without any normalization. We also show convergence of all moments of the $f$-vector of $C_n$ and identify the limiting constants for the expectations. We prove that the expected Grassmann angles of $C_n$ can be expressed through the expected $f$-vector. This yields convergence of expected Grassmann angles and conic intrinsic volumes and answers thereby a question of B\\'ar\\'any, Hug, Reitzner and Schneider [Random points in halfspheres, Rand. Struct. Alg., 2017]. Our approach is based on the observation that the random cone $C_n$ weakly converges, after a suitable rescaling, to a random cone whose intersection with the tangent hyperplane of the half-sphere at its north pole is the convex hull of the Poisson point process with power-law intensity function proportional to $\\|x\\|^{-(d+\\gamma)}$, where $\\gamma=1$. We compute the expected number of facets, the expected intrinsic volumes and the expected $T$-functional of this random convex hull for arbitrary $\\gamma>0$.", "revisions": [ { "version": "v1", "updated": "2018-01-24T14:53:29.000Z" } ], "analyses": { "subjects": [ "52A22", "60D05", "52A55", "52B11", "60F05" ], "keywords": [ "poisson point process", "random points", "expected grassmann angles", "random cone", "power-law intensity function proportional" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }