(I)-envelopes of unit balls and James' characterization of reflexivity

Volume 182 / 2007

Ondřej F. K. Kalenda Studia Mathematica 182 (2007), 29-40 MSC: Primary 46B26; Secondary 46A55, 46B10. DOI: 10.4064/sm182-1-2


We study the (I)-envelopes of the unit balls of Banach spaces. We show, in particular, that any nonreflexive space can be renormed in such a way that the (I)-envelope of the unit ball is not the whole bidual unit ball. Further, we give a simpler proof of James' characterization of reflexivity in the nonseparable case. We also study the spaces in which the (I)-envelope of the unit ball adds nothing.


  • Ondřej F. K. KalendaDepartment of Mathematical Analysis
    Faculty of Mathematics and Physics
    Charles University
    Sokolovská 83
    186 75 Praha 8, Czech Republic

Search for IMPAN publications

Query phrase too short. Type at least 4 characters.

Rewrite code from the image

Reload image

Reload image