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arXiv · 1812.07825

On the non-embedding of $\ell_1$ in the James Tree Space

Ioakeim Ampatzoglou
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Abstract

James Tree Space ($\mathcal{JT}$), introduced by R. James, is the first Banach space constructed having non-separable conjugate and not containing $\ell^1$. James actually proved that every infinite dimensional subspace of $\mathcal{JT}$ contains a Hilbert space, which implies the $\ell^1$ non-embedding. In this expository article, we present a direct proof of the $\ell^1$ non-embedding, using Rosenthal's $\ell^1$- Theorem and some measure theoretic arguments, namely Riesz's Representation Theorem.

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Ioakeim Ampatzoglou. 2018-12-19. On the non-embedding of $\ell_1$ in the James Tree Space. https://arxiv.org/abs/1812.07825

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