This is an announcement for the paper "Optimal domain of $q$-concave
operators and vector measure representation of $q$-concave Banach
lattices" by O. Delgado and E.A. Sanchez Perez.
Abstract:
Given a Banach space valued $q$-concave linear operator $T$ defined on a
$\sigma$-order continuous quasi-Banach function space, we provide a
description of the optimal domain of $T$ preserving $q$-concavity, that
is, the largest $\sigma$-order continuous quasi-Banach function space
to which $T$ can be extended as a $q$-concave operator. We show in this
way the existence of maximal extensions for $q$-concave operators. As
an application, we show a representation theorem for $q$-concave Banach
lattices through spaces of integrable functions with respect to a vector
measure. This result culminates a series of representation theorems for
Banach lattices using vector measures that have been obtained in the
last twenty years.
Archive classification: math.FA
Mathematics Subject Classification: 47B38, 46G10, 46E30, 46B42
Submitted from: easancpe(a)mat.upv.es
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1511.02337
or
http://arXiv.org/abs/1511.02337
This is an announcement for the paper "1-Grothendieck $C(K)$ spaces"
by Jindrich Lechner.
Abstract:
A Banach space is said to be Grothendieck if weak and weak$^*$
convergent sequences in the dual space coincide. This notion has been
quantificated by H. Bendov\'{a}. She has proved that $\ell_\infty$ has
the quantitative Grothendieck property, namely, it is 1-Grothendieck. Our
aim is to show that Banach spaces from a certain wider class are
1-Grothendieck, precisely, $C(K)$ is 1-Grothendieck provided $K$ is
a totally disconnected compact space such that its algebra of clopen
subsets has the so called Subsequential completeness property.
Archive classification: math.FA
Submitted from: jindrich.lechner(a)seznam.cz
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1511.02202
or
http://arXiv.org/abs/1511.02202
This is an announcement for the paper "The trace as an average over the
unit sphere of a normed space with a 1-symmetric basis" by Tomasz Kania
and Kent E. Morrison.
Abstract:
We generalise the formula expressing the matrix trace of a given square
matrix as the integral of the numerical values of $A$ over the Euclidean
sphere to the unit spheres of finite-dimensional normed spaces that have
a 1-symmetric basis. Our result is new even in the case of $\ell_p$-norms
in $\mathbb{R}^N$ for $p\neq 2$.
Archive classification: math.FA math.CA
Mathematics Subject Classification: 15A60, 47A12
Submitted from: kmorriso(a)calpoly.edu
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1511.02084
or
http://arXiv.org/abs/1511.02084
This is an announcement for the paper "John's ellipsoid and the integral
ratio of a log-concave function" by David Alonso-Gutierrez, Bernardo
Gonzalez Merino, Carlos Hugo Jimenez, and Rafael Villa.
Abstract:
We extend the notion of John's ellipsoid to the setting of integrable
log-concave functions. This will allow us to define the integral ratio
of a log-concave function, which will extend the notion of volume ratio,
and we will find the log-concave function maximizing the integral ratio. A
reverse functional a?ne isoperimetric inequality will be given, written in
terms of this integral ratio. This can be viewed as a stability version
of the functional affine isoperimetric inequality.
Archive classification: math.FA
Submitted from: bg.merino(a)tum.de
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1511.01266
or
http://arXiv.org/abs/1511.01266
This is an announcement for the paper "Riemann integrability versus weak
continuity" by Gonzalo Martinez-Cervantes.
Abstract:
In this paper we focus on the relation between Riemann integrability and
weak continuity. A Banach space $X$ is said to have the weak Lebesgue
property if every Riemann integrable function from $[0,1]$ into $X$
is weakly continuous almost everywhere. We prove that the weak Lebesgue
property is stable under $\ell_1$-sums and obtain new examples of Banach
spaces with and without this property. Furthermore, we characterize
Dunford-Pettis operators in terms of Riemann integrability and provide
a quantitative result about the size of the set of $\tau$-continuous
non Riemann integrable functions, with $\tau$ a locally convex topology
weaker than the norm topology.
Archive classification: math.FA
Mathematics Subject Classification: 46G10, 28B05, 03E10
Submitted from: gonzalo.martinez2(a)um.es
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1510.08801
or
http://arXiv.org/abs/1510.08801
This is an announcement for the paper "Compact convex sets that admit
a lower semicontinuous strictly convex function" by L. Garcia-Lirola,
J. Orihuela, and M. Raja.
Abstract:
We study the class of compact convex subsets of a topological vector
space which admits a strictly convex and lower semicontinuous function. We
prove that such a compact set is embeddable in a strictly convex dual
Banach space endowed with its weak$^*$ topology. In addition, we find
exposed points where a strictly convex lower semicontinuous function
is continuous.
Archive classification: math.FA
Mathematics Subject Classification: 46A55 (Primary) 46B03, 54E35
(Secondary)
Remarks: 9 pages
Submitted from: luiscarlos.garcia(a)um.es
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1510.07921
or
http://arXiv.org/abs/1510.07921
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
This is an announcement for the paper "Distortion in the finite
determination result for embeddings of finite metric spaces into Banach
spaces" by Sofiya Ostrovska and Mikhail I. Ostrovskii.
Abstract:
Given a Banach space $X$ and a locally finite metric space $A$, it is
known that if all finite subsets of $A$ admit bilipschitz embeddings
into $X$ with distortions $\le C$, then the space $A$ itself admits
an embedding into $X$ with distortion $\le D\cdot C$, where $D$ is
an absolute constant. The goal of this paper is to show that $D>1$,
implying that, in general, there is a ``deterioration of distortion''
in the aforementioned situations.
Archive classification: math.FA math.MG
Mathematics Subject Classification: 46B85, 46B20
Submitted from: ostrovsm(a)stjohns.edu
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1510.05974
or
http://arXiv.org/abs/1510.05974