Carathodory's theorem in depth

Let X be a finite set of points in RdRd . The Tukey depth of a point q with respect to X is the minimum number tX(q)tX(q) of points of X in a halfspace containing q. In this paper we prove a depth version of Carathéodory’s theorem. In particular, we prove that there exist a constant c (that depends...

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Detalles Bibliográficos
Autores: Fabila Monroy, Ruy, Huemer, Clemens|||0000-0001-7557-0823
Tipo de recurso: artículo
Fecha de publicación:2017
País:España
Institución:Universitat Politècnica de Catalunya (UPC)
Repositorio:UPCommons. Portal del coneixement obert de la UPC
Idioma:inglés
OAI Identifier:oai:upcommons.upc.edu:2117/111689
Acceso en línea:https://hdl.handle.net/2117/111689
https://dx.doi.org/10.1007/s00454-017-9893-8
Access Level:acceso abierto
Palabra clave:Convex geometry
Helly type theorem
Tukey depth
Simplicial depth
Teoremes
Classificació AMS::32 Several complex variables and analytic spaces::32F Geometric convexity
Àrees temàtiques de la UPC::Matemàtiques i estadística::Anàlisi matemàtica
Descripción
Sumario:Let X be a finite set of points in RdRd . The Tukey depth of a point q with respect to X is the minimum number tX(q)tX(q) of points of X in a halfspace containing q. In this paper we prove a depth version of Carathéodory’s theorem. In particular, we prove that there exist a constant c (that depends only on d and tX(q)tX(q) ) and pairwise disjoint sets X1,…,Xd+1¿XX1,…,Xd+1¿X such that the following holds. Each XiXi has at least c|X| points, and for every choice of points xixi in XiXi , q is a convex combination of x1,…,xd+1x1,…,xd+1 . We also prove depth versions of Helly’s and Kirchberger’s theorems.