On Super Weak Compactness of Subsets and its Equivalences in Banach Spaces
Journal of convex analysis, Tome 25 (2018) no. 3, pp. 899-926
Analogous to weak compactness of subsets of Banach spaces and to property of subsets in super reflexive spaces, the purpose of this paper is to discuss super weak compactness of both convex and nonconvex subsets in Banach spaces. As a result, we give three characterizations of super weakly compact sets: The first one is Grothendiek's type theorem; the second one is James' type characterization and the last one is super Banach-Saks property. We also show that super weak compactness, finite index property and finite dual index property of a closed convex set are actually equivalent. Therefore, eleven notions and properties eventually coincide for a closed bounded convex set. We also present some characterizations of uniformly weakly null sequences. These are done by localizing some basic properties of ultrapowers and using some geometric procedures of Banach spaces.
Classification :
46B20, 46B03, 46B50
Mots-clés : Super weakly compact set, super Banach-Saks set, finite index, finite dual index, ultraproduct, Banach space
Mots-clés : Super weakly compact set, super Banach-Saks set, finite index, finite dual index, ultraproduct, Banach space
@article{JCA_2018_25_3_JCA_2018_25_3_a9,
author = {L. Cheng and Q. Cheng and S. Luo and K. Tu and J. Zhang},
title = {On {Super} {Weak} {Compactness} of {Subsets} and its {Equivalences} in {Banach} {Spaces}},
journal = {Journal of convex analysis},
pages = {899--926},
year = {2018},
volume = {25},
number = {3},
url = {http://geodesic.mathdoc.fr/item/JCA_2018_25_3_JCA_2018_25_3_a9/}
}
TY - JOUR AU - L. Cheng AU - Q. Cheng AU - S. Luo AU - K. Tu AU - J. Zhang TI - On Super Weak Compactness of Subsets and its Equivalences in Banach Spaces JO - Journal of convex analysis PY - 2018 SP - 899 EP - 926 VL - 25 IS - 3 UR - http://geodesic.mathdoc.fr/item/JCA_2018_25_3_JCA_2018_25_3_a9/ ID - JCA_2018_25_3_JCA_2018_25_3_a9 ER -
%0 Journal Article %A L. Cheng %A Q. Cheng %A S. Luo %A K. Tu %A J. Zhang %T On Super Weak Compactness of Subsets and its Equivalences in Banach Spaces %J Journal of convex analysis %D 2018 %P 899-926 %V 25 %N 3 %U http://geodesic.mathdoc.fr/item/JCA_2018_25_3_JCA_2018_25_3_a9/ %F JCA_2018_25_3_JCA_2018_25_3_a9
L. Cheng; Q. Cheng; S. Luo; K. Tu; J. Zhang. On Super Weak Compactness of Subsets and its Equivalences in Banach Spaces. Journal of convex analysis, Tome 25 (2018) no. 3, pp. 899-926. http://geodesic.mathdoc.fr/item/JCA_2018_25_3_JCA_2018_25_3_a9/