Characterizations of $L^1$-predual spaces by centerable subsets
Commentationes Mathematicae Universitatis Carolinae, Tome 48 (2007) no. 2, pp. 239-243
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In this note, we prove that a real or complex Banach space $X$ is an $L^1$-predual space if and only if every four-point subset of $X$ is centerable. The real case sharpens Rao's result in [{\it Chebyshev centers and centerable sets\/}, Proc. Amer. Math. Soc. {\bf 130} (2002), no. 9, 2593--2598] and the complex case is closely related to the characterizations of $L^1$-predual spaces by Lima [{\it Complex Banach spaces whose duals are $L_1$-spaces\/}, Israel J. Math. {\bf 24} (1976), no. 1, 59--72].
In this note, we prove that a real or complex Banach space $X$ is an $L^1$-predual space if and only if every four-point subset of $X$ is centerable. The real case sharpens Rao's result in [{\it Chebyshev centers and centerable sets\/}, Proc. Amer. Math. Soc. {\bf 130} (2002), no. 9, 2593--2598] and the complex case is closely related to the characterizations of $L^1$-predual spaces by Lima [{\it Complex Banach spaces whose duals are $L_1$-spaces\/}, Israel J. Math. {\bf 24} (1976), no. 1, 59--72].
Classification :
41A65, 46B20
Keywords: Chebyshev radius; centerable subsets and $L^1 $-predual spaces
Keywords: Chebyshev radius; centerable subsets and $L^1 $-predual spaces
@article{CMUC_2007_48_2_a5,
author = {Duan, Yanzheng and Lin, Bor-Luh},
title = {Characterizations of $L^1$-predual spaces by centerable subsets},
journal = {Commentationes Mathematicae Universitatis Carolinae},
pages = {239--243},
year = {2007},
volume = {48},
number = {2},
mrnumber = {2338092},
zbl = {1199.41181},
language = {en},
url = {http://geodesic.mathdoc.fr/item/CMUC_2007_48_2_a5/}
}
TY - JOUR AU - Duan, Yanzheng AU - Lin, Bor-Luh TI - Characterizations of $L^1$-predual spaces by centerable subsets JO - Commentationes Mathematicae Universitatis Carolinae PY - 2007 SP - 239 EP - 243 VL - 48 IS - 2 UR - http://geodesic.mathdoc.fr/item/CMUC_2007_48_2_a5/ LA - en ID - CMUC_2007_48_2_a5 ER -
Duan, Yanzheng; Lin, Bor-Luh. Characterizations of $L^1$-predual spaces by centerable subsets. Commentationes Mathematicae Universitatis Carolinae, Tome 48 (2007) no. 2, pp. 239-243. http://geodesic.mathdoc.fr/item/CMUC_2007_48_2_a5/