Ellipsoidal Cones in Normed Vector Spaces
Journal of convex analysis, Tome 24 (2017) no. 3, pp. 795-805
The characterization of ellipsoids is intimately tied to characterizing the Banach spaces that are Hilbert spaces. We give two characterizations of cones over ellipsoids in real normed vector spaces. Let $C$ be a closed convex cone with nonempty interior such that $C$ has a bounded section of codimension $1$. We show that $C$ is a cone over an ellipsoid if and only if every bounded section of $C$ has a center of symmetry. We also show that $C$ is a cone over an ellipsoid if and only if the affine span of $\partial C \cap \partial(a - C)$ has codimension $1$ for every point $a$ in the interior of $C$. These results generalize the finite-dimensional cases proved by J. Jer{\'o}nimo-Castro and T. B. McAllister [\emph{Two characterizations of ellipsoidal cones}, J. Convex Analysis 20 (2013) 1181--1187].
Classification :
46B20, 52A50, 46B40, 46B10
Mots-clés : Ellipsoidal cone, ordered normed linear space, centrally symmetric convex body
Mots-clés : Ellipsoidal cone, ordered normed linear space, centrally symmetric convex body
@article{JCA_2017_24_3_JCA_2017_24_3_a3,
author = {F. Jafari and T. B. McAllister},
title = {Ellipsoidal {Cones} in {Normed} {Vector} {Spaces}},
journal = {Journal of convex analysis},
pages = {795--805},
year = {2017},
volume = {24},
number = {3},
url = {http://geodesic.mathdoc.fr/item/JCA_2017_24_3_JCA_2017_24_3_a3/}
}
F. Jafari; T. B. McAllister. Ellipsoidal Cones in Normed Vector Spaces. Journal of convex analysis, Tome 24 (2017) no. 3, pp. 795-805. http://geodesic.mathdoc.fr/item/JCA_2017_24_3_JCA_2017_24_3_a3/