This is an announcement for the paper "Towards Banach space strong
property (T) for SL(3,R)" by Mikael de la Salle.
Abstract: We prove that SL(3,R) has strong property (T) in Lafforgue's
sense with respect to the Banach spaces that are \theta>0 interpolation
spaces (for the Lions-Calder\'on complex interpolation method) between
an arbitrary Banach space and a Banach space with sufficiently
good type and cotype. As a consequence, for such a Banach space
X, SL(3,R) and its lattices have the fixed point property (F_X) of
Bader--Furman--Gelander--Monod, and the expanders contructed from SL(3,Z)
do not admit a coarse embedding into X. We also prove a quantitative
decay of matrix coefficients (Howe-Moore property) for representations
with small exponential growth of SL(3,R) on X.
This class of Banach spaces contains the classical superreflexive spaces
and some nonreflexive spaces as well. We see no obstruction for this
class to be equal to all spaces with nontrivial type.
Archive classification: math.GR math.FA math.MG
Remarks: 31 pages, 3 figures. Comments welcome!
Submitted from: delasall(a)phare.normalesup.org
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1307.2475
or
http://arXiv.org/abs/1307.2475
This is an announcement for the paper "Basic sequences and spaceability
in $\ell_p$ spaces" by Daniel Cariello and Juan B. Seoane-Sepulveda.
Abstract: Let $X$ be a sequence space and denote by $Z(X)$ the
subset of $X$ formed by sequences having only a finite number of
zero coordinates. We study algebraic properties of $Z(X)$ and show
(among other results) that (for $p \in [1,\infty]$) $Z(\ell_p)$ does
not contain infinite dimensional closed subspaces. This solves an open
question originally posed by R. M. Aron and V. I. Gurariy in 2003 on
the linear structure of $Z(\ell_\infty)$.
In addition to this, we also give a thorough analysis of the existing
algebraic structures within the set $X \setminus Z(X)$ and its algebraic
genericity.
Archive classification: math.FA
Remarks: 17 pages
Submitted from: jseoane(a)mat.ucm.es
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1307.2508
or
http://arXiv.org/abs/1307.2508
This is an announcement for the paper "Free spaces over countable compact
metric spaces" by Aude Dalet.
Abstract: We prove that the Lipschitz-free space over a countable
compact metric space is isometric to a dual space and has the metric
approximation property.
Archive classification: math.FA
Submitted from: aude.dalet(a)univ-fcomte.fr
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1307.0735
or
http://arXiv.org/abs/1307.0735
This is an announcement for the paper "The Bishop-Phelps-Bollob\'as
property for operators between spaces of continuous functions" by Maria
Acosta, Julio Becerra, Yun Sung Choi, Maciej Ciesielski, Sun Kwang Kim,
Han Ju Lee, and Miguel Martin.
Abstract: We show that the space of bounded and linear operators between
spaces of continuous functions on compact Hausdorff topological spaces
has the Bishop-Phelps-Bollob\'as property. A similar result is also
proved for the class of compact operators from the space of continuous
functions vanishing at infinity on a locally compact and Hausdorff
topological space into a uniformly convex space, and for the class of
compact operators from a Banach space into a predual of an $L_1$-space.
Archive classification: math.FA
Mathematics Subject Classification: 46B04
Submitted from: mmartins(a)ugr.es
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1306.6740
or
http://arXiv.org/abs/1306.6740
1st ANNOUNCEMENT OF SUMIRFAS 2013
The Informal Regional Functional Analysis Seminar
August 2-4
Texas A&M University, College Station
Schedule: Talks for SUMIRFAS will be posted on the Workshop in Analysis
and Probability page, whose URL is
http://www.math.tamu.edu/~kerr/workshop/
The first talk will be in the early afternoon on Friday and the Seminar
concludes by lunch time on Sunday. All talks will be in Blocker 169. The
Blocker Building is on Ireland St. just south of University Dr. on the
Texas A&M campus:
http://www.math.tamu.edu/contact/blocker.html.
Coffee and refreshments will be available in Blocker 148.
SUMIRFAS 2013 is dedicated to the memory of Ted Odell, who was one of the
organizers of the UTAMIRFAS, the predecessor of SUMIRFAS. Ted served with
distinction on the advisory board of the Workshop from its beginning until
his untimely passing in January.
The Plenary speakers at SUMIRFAS 2013 are Stephen Dilworth, Steve Jackson,
Masoud Khalkhali, Thomas Schlumprecht, Nicole Tomczak-Jaegermann, and
Wilhelm Winter. Other speakers include Tim Rainone, Paul Skoufranis, and
John Williams.
August 5-9 there will be a Concentration Week on "Dynamics, Geometry, and
Operator Algebras", organized by David Kerr and Guoliang Yu. This
Concentration Week aims to promote connections between nuclearity, nuclear
dimension, group C*-algebras and crossed products, topological and
measurable dynamics, algebraic dynamics, entropy, dimensional ideas from
coarse geometry, and K-theory with applications to topology. The program
will feature lecture series by David Kerr, Stuart White, and Rufus
Willett. The URL for this Concentration Week is
http://www.math.tamu.edu/~kerr/concweek13/
Immediately preceding SUMIRFAS, on August 1, there will be a celebration
of "The Mathematical Legacy of Ted Odell", organized by Thomas
Schlumprecht. The URL for this activity is
http://math.slu.edu/~freeman/LegacyConference/
The Workshop is supported in part by grants from the National Science
Foundation (NSF). Minorities, women, graduate students, and young
researchers are especially encouraged to attend.
For logistical support, including requests for support, please contact
Cara Barton <cara(a)math.tamu.edu>. For more information on the Workshop
itself, please contact William Johnson <johnson(a)math.tamu.edu>, David Kerr
<kerr(a)math.tamu.edu>, or Gilles Pisier <pisier(a)math.tamu.edu>.
For information about the Concentration Week on "Dynamics, Geometry, and
Operator Algebras" contact David Kerr <kerr(a)math.tamu.edu>.
For information about the day devoted to "The Mathematical Legacy of Ted
Odell" contact Thomas Schlumprecht <schlump(a)math.tamu.edu>
This is an announcement for the paper "Radon-Nikod\'ym property and
thick families of geodesics" by Mikhail I. Ostrovskii.
Abstract: Banach spaces without the Radon-Nikod\'ym property are
characterized as spaces containing bilipschitz images of thick families of
geodesics defined as follows. A family $T$ of geodesics joining points $u$
and $v$ in a metric space is called {\it thick} if there is $\alpha>0$
such that for every $g\in T$ and for any finite collection of points
$r_1,\dots,r_n$ in the image of $g$, there is another $uv$-geodesic
$\widetilde g\in T$ satisfying the conditions: $\widetilde g$ also
passes through $r_1,\dots,r_n$, and, possibly, has some more common
points with $g$. On the other hand, there is a finite collection of
common points of $g$ and $\widetilde g$ which contains $r_1,\dots,r_n$
and is such that the sum of maximal deviations of the geodesics between
these common points is at least $\alpha$.
Archive classification: math.FA math.MG
Mathematics Subject Classification: 46B22, 46B85, 54E35
Submitted from: ostrovsm(a)stjohns.edu
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1306.5807
or
http://arXiv.org/abs/1306.5807
This is an announcement for the paper "On the metric entropy of the
Banach-Mazur compactum" by Gilles Pisier.
Abstract: We study of the metric entropy of the metric space $\cl B_n$ of
all $n$-dimensional Banach spaces (the so-called Banach-Mazur compactum)
equipped with the Banach-Mazur (multiplicative) ``distance" $d$. We
are interested either in estimates independent of the dimension or in
asymptotic estimates when the dimension tends to $\infty$. For instance,
we prove that, if $N({\cl B_n},d, 1+\vp)$ is the smallest number of
``balls" of ``radius" $1+\vp$ that cover $\cl B_n$, then for any $\vp>0$
we have $$0<\liminf_{n\to \infty} \log\log N(\cl B_n,d,1+\vp)\le
\limsup_{n\to \infty} \log\log N(\cl B_n,d,1+\vp)<\infty.$$ We also
prove similar results for the matricial operator space analogues.
Archive classification: math.FA
Submitted from: pisier(a)math.jussieu.fr
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1306.5325
or
http://arXiv.org/abs/1306.5325
This is an announcement for the paper "Interlacing families II: Mixed
characteristic polynomials and a question of Kadison and Singer" by Adam
Marcus, Daniel A Spielman, and Nikhil Srivastava.
Abstract: We use the method of interlacing families of polynomials
to prove Weaver's conjecture KS_2, which is known to imply a positive
answer to a famous question of Kadison and Singer via Anderson's Paving
Conjecture. Our proof goes through an analysis of the largest roots of a
family of polynomials that we call the "mixed characteristic polynomials"
of a collection of matrices.
Archive classification: math.CO math.FA math.OA
Submitted from: spielman(a)cs.yale.edu
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1306.3969
or
http://arXiv.org/abs/1306.3969
This is an announcement for the paper "Unbounded order convergence
and application to martingales without probability" by Niushan Gao and
Foivos Xanthos.
Abstract: A net $(x_\alpha)_{\alpha\in \Gamma}$ in a vector lattice $X$
is unbounded order convergent (uo-convergent) to $x$ if $|x_\alpha-x|
\wedge y \xrightarrow{{o}} 0$ for each $y \in X_+$, and is unbounded
order Cauchy (uo-Cauchy) if the net $(x_\alpha-x_{\alpha'})_{\Gamma\times
\Gamma}$ is uo-convergent to $0$. In the first part of this article,
we study uo-convergent and uo-Cauchy nets in Banach lattices and use
them to characterize Banach lattices with the positive Schur property and
KB-spaces. In the second part, we use the concept of uo-Cauchy sequences
to extend Doob's submartingale convergence theorems to a measure-free
setting. Our results imply, in particular, that every norm bounded
submartingale in $L_1(\Omega;F)$ is almost surely uo-Cauchy in $F$,
where $F$ is an order continuous Banach lattice with a weak unit.
Archive classification: math.FA
Submitted from: foivos(a)ualberta.ca
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1306.2563
or
http://arXiv.org/abs/1306.2563