Results 31 to 40 of about 375 (53)
The optimality of James’s distortion theorems
, 1997 A renorming of `1, explored here in detail, shows that the copies of `1 produced in the proof of the Kadec-Pe lczynski theorem inside nonreflexive subspaces of L1[0, 1] cannot be produced inside general nonreflexive spaces that contain copies of `1.
P. Dowling +3 more
semanticscholar +1 more source
Smooth norms that depend locally on finitely many coordinates
, 1995 We characterize separable normed spaces that admit equivalent COO-smooth norms depending locally on finitely many coordinates. It follows, in particular, that such norms exist on any normed space with countable algebraic basis.
P. Hájek
semanticscholar +1 more source
More (\ell_r) saturated (\mathcal{L}_\infty) spaces [PDF]
arXiv, 2010 We present some new examples of separable (\mathcal_\infty) spaces which are (\ell_r) saturated for some (1 < r < \infty).
arxiv
The structure of Lindenstrauss–Pełczyński spaces
, 2009 Lindenstrauss–Pełczyński (for short LP) spaces were introduced by these authors [Studia Math. 174 (2006)] as those Banach spaces X such that every operator from a subspace of c0 into X can be extended to the whole c0.
J. Castillo +2 more
semanticscholar +1 more source
Generalization of a theorem of Zippin [PDF]
arXiv, 2017 We generalize and prove a result which was first shown by Zippin, and was explicitly formulated by Benyamini.
arxiv
Analytic norms in Orlicz spaces
, 2000 It is shown that an Orlicz sequence space hM admits an equivalent analytic renorming if and only if it is either isomorphic to l2n or isomorphically polyhedral.
S. Troyanski, P. Hájek
semanticscholar +1 more source
Characterizing Hilbert space frames with the subframe property [PDF]
41 No. 4 (1997) Illinois J. Math, p 648-666, 1998 We characterize Riesz frames and frames with the subframe property and use this to answer most of the questions from the literature concerning these properties and their relationships to the projection methods etc.
arxiv
On the complemented subspaces of the Schreier spaces [PDF]
arXiv, 1999 It is shown that the Schreier space X admits a set of continuum cardinality whose elements are mutually incomparable complemented subspaces spanned by subsequences of the natural Schauder basis of X.
arxiv
Subspaces of c_0 and Lipschitz isomorphisms [PDF]
arXiv, 1999 We show that the class of subspaces of c_0 is stable under Lipschitz isomorphisms. The main corollary is that any Banach space which is Lipschitz isomorphic to c_0 is linearly isomorphic to c_0.
arxiv
Szlenk indices and uniform homeomorphisms [PDF]
arXiv, 1999 We prove some rather precise renorming theorems for Banach spaces with Szlenk index $\omega_0$. We use these theorems to show the invariance of certain quantitative Szlenk-type indices under uniform homeomorphisms.
arxiv