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Journal of Convex Analysis 24 (2017), No. 2, 685--693 Copyright Heldermann Verlag 2017 Convex Bodies with Many Elliptic Sections Isaac Arelio Instituto de Matemáticas UNAM, Circuito Ext. Cd. Universitaria, Colonia Copilco el Bajo, México D.F. - C.P. 04510 incordio@im.unam.mx Luis Montejano Instituto de Matemáticas UNAM, Circuito Ext. Cd. Universitaria, Colonia Copilco el Bajo, México D.F. - C.P. 04510 luis@matem.unam.mx We show in this paper that two normal elliptic sections through every point of the boundary of a smooth convex body essentially characterize an ellipsoid and furthermore, that four different pairwise non-tangent elliptic sections through every point of the C2-differentiable boundary of a convex body also essentially characterize an ellipsoid. Keywords: Convex surface, quadric surface, quadric curve,planar section, characterization of ellipsoid. MSC: 52A15, 53A04, 53A05 [ Fulltext-pdf (1420 KB)] for subscribers only. |