We study strict u-ideals in Banach spaces. A Banach space X is a strict u-ideal in its bidual when the canonical decomposition is unconditional. We characterize Banach spaces which are strict u-ideals in their bidual and show that if X is a strict u-ideal in a Banach space Y then X contains c₀. We also show that is not a u-ideal.
@article{bwmeta1.element.bwnjournal-article-doi-10_4064-sm195-3-6, author = {Vegard Lima and \AA svald Lima}, title = {Strict u-ideals in Banach spaces}, journal = {Studia Mathematica}, volume = {192}, year = {2009}, pages = {275-285}, zbl = {1190.46015}, language = {en}, url = {http://dml.mathdoc.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-sm195-3-6} }
Vegard Lima; Åsvald Lima. Strict u-ideals in Banach spaces. Studia Mathematica, Tome 192 (2009) pp. 275-285. http://gdmltest.u-ga.fr/item/bwmeta1.element.bwnjournal-article-doi-10_4064-sm195-3-6/