This is an announcement for the paper "The intrinsic metric on the unit
sphere of a normed space" by Miek Messerschmidt and Marten Wortel.
Abstract:
Let $S$ denote the unit sphere of a real normed space. We show that the
intrinsic metric on $S$ is strongly equivalent to the induced
metric on $S$. Specifically, for all $x,y\in S$, \[ \|x-y\|\leq
d(x,y)\leq\sqrt{2}\pi\|x-y\|, \] where $d$ denotes the intrinsic metric
on $S$.
Archive classification: math.FA math.MG
Mathematics Subject Classification: Primary:46B10. Secondary: 51F99, 46B07
Submitted from: mmesserschmidt(a)gmail.com
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1510.07442
or
http://arXiv.org/abs/1510.07442
This is an announcement for the paper "On Dvoretzky's theorem for
subspaces of $L_p$" by Grigoris Paouris and Petros Valettas.
Abstract:
We prove that for any $p > 2$ and every $n$-dimensional subspace $X$ of
$L_p$, the Euclidean space $\ell_2^k$ can be $(1 + \varepsilon)$-embedded
into $X$ with $k \geq c_p \min\{\varepsilon^2 n, (\varepsilon n)^{2/p}
\}$, where $c_p > 0$ is a constant depending only on $p$.
Archive classification: math.FA math.MG
Mathematics Subject Classification: 46B07, 46B09
Remarks: 20 pages
Submitted from: valettasp(a)missouri.edu
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1510.07289
or
http://arXiv.org/abs/1510.07289
This is an announcement for the paper "Random version of Dvoretzky's
theorem in $\ell_p^n$" by Grigoris Paouris, Petros Valettas and Joel Zinn.
Abstract:
We study the dependence on $\varepsilon$ in the critical dimension
$k(n, p, \varepsilon)$ that one can find random sections of the
$\ell_p^n$-ball which are $(1+\varepsilon)$-spherical. For any fixed $n$
we give lower estimates for $k(n, p, \varepsilon)$ for all eligible
values $p$ and $\varepsilon$, which agree with the sharp estimates
for the extreme values $p = 1$ and $p = \infty$. In order to do so,
we provide bounds for the gaussian concentration of the $\ell_p$-norm.
Archive classification: math.FA
Mathematics Subject Classification: 46B06, 46B07, 46B09
Remarks: 45 pages
Submitted from: valettasp(a)missouri.edu
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1510.07284
or
http://arXiv.org/abs/1510.07284