{ "id": "1708.01510", "version": "v1", "published": "2017-08-03T12:00:45.000Z", "updated": "2017-08-03T12:00:45.000Z", "title": "A ball characterization in spaces of constant curvature", "authors": [ "J. Jerónimo-Castro", "E. Makai Jr" ], "comment": "30 pages. arXiv admin note: text overlap with arXiv:1601.04494", "categories": [ "math.MG" ], "abstract": "High proved the following theorem. If the intersections of any two congruent copies of a plane convex body are centrally symmetric, then this body is a circle. In our paper we extend the theorem of High to spherical, Euclidean and hyperbolic spaces, under some regularity assumptions. If in any of these spaces there is a pair of closed convex sets of class $C^2_+$ with interior points, different from the whole space, and the intersections of any congruent copies of these sets are centrally symmetric, then our sets are congruent balls.", "revisions": [ { "version": "v1", "updated": "2017-08-03T12:00:45.000Z" } ], "analyses": { "subjects": [ "52A55", "52A20" ], "keywords": [ "constant curvature", "ball characterization", "congruent copies", "plane convex body", "centrally symmetric" ], "note": { "typesetting": "TeX", "pages": 30, "language": "en", "license": "arXiv", "status": "editable" } } }