This is an announcement for the paper "The generalized roundness of $\ell_\infty^{(3)}$ revisited" by Ian Doust, Stephen Sanchez and Anthony Weston.
Abstract: Metric spaces of generalized roundness zero have interesting non-embedding properties. For instance, we note that no metric space of generalized roundness zero is isometric to any metric subspace of any $L_{p}$-space for which $0 < p \leq 2$. Lennard, Tonge and Weston gave an indirect proof that $\ell_{\infty}^{(3)}$ has generalized roundness zero by appealing to highly non-trivial isometric embedding theorems of Bretagnolle Dacunha-Castelle and Krivine, and Misiewicz. In this paper we give a direct proof that $\ell_{\infty}^{(3)}$ has generalized roundness zero. This provides insight into the combinatorial geometry of $\ell_{\infty}^{(3)}$ that causes the generalized roundness inequalities to fail. We complete the paper by noting a characterization of real quasi-normed spaces of generalized roundness zero.
Archive classification: math.FA
Mathematics Subject Classification: 46B20
Remarks: 8 pages
Submitted from: i.doust@unsw.edu.au
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1401.4095
or