Schroeder-Bernstein Quintuples for Banach Spaces

• Autorzy: Elói Medina Galego
• Języki publikacji: EN

Abstrakty

EN

Let X and Y be two Banach spaces, each isomorphic to a complemented subspace of the other. In 1996, W. T. Gowers solved the Schroeder-Bernstein Problem for Banach spaces by showing that X is not necessarily isomorphic to Y. In this paper, we obtain necessary and sufficient conditions on the quintuples (p,q,r,s,t) in ℕ for X to be isomorphic to Y whenever
⎧$X ~ X^p ⊕ Y^q$,
⎨
⎩ $Y^t ~ X^r ⊕ Y^s$.
Such quintuples are called Schroeder-Bernstein quintuples for Banach spaces and they yield a unification of the known decomposition methods in Banach spaces involving finite sums of X and Y, similar to Pełczyński's decomposition method. Inspired by this result, we also introduce the notion of Schroeder-Bernstein sextuples for Banach spaces and pose a conjecture which would complete their characterization.

Kategorie tematyczne

• 46B20: Geometry and structure of normed linear spaces
• 46B03: Isomorphic theory (including renorming) of Banach spaces

• Wydawca: Institute of Mathematics Polish Academy of Sciences
• Czasopismo: Bulletin of the Polish Academy of Sciences. Mathematics
• Rocznik: 2006
• Tom: 54
• Numer: 2
• Strony: 113-124

Daty

wydano

2006

Twórcy

autor

Elói Medina Galego

• Department of Mathematics - IME, University of São Paulo, São Paulo 05315-970, Brazil

Identyfikatory

DOI

10.4064/ba54-2-3