This is an announcement for the paper "Random series of trace class
operators" by Gilles Pisier.
Abstract: In this lecture, we present some results on Gaussian (or
Rademacher) random series of trace class operators, mainly due jointly
with F. Lust-Piquard. We will emphasize the probabilistic reformulation of
these results, as well as the open problems suggested by them. We start
by a brief survey of what is known about the problem of characterizing
a.s. convergent (Gaussian or Rademacher) series of random vectors in a
Banach space. The main result presented here is that for certain pairs
of Banach spaces $E,F$ that include Hilbert spaces
(and type 2 spaces with the analytic UMD property), we have $$
R(E\widehat\otimes F) =R(E)\widehat\otimes F + E\widehat\otimes R(F)
$$ where $R(E)$ denotes the space of convergent Rademacher series with
coefficients in $E$ and
$E\widehat\otimes F$ denotes the projective tensor product.
Archive classification: math.FA math.OA math.PR
Mathematics Subject Classification: 46B09
Citation: Proceedings Cuarto CLAPEM Mexico 1990. Contribuciones en
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1103.2090
or
http://arXiv.org/abs/1103.2090
This is an announcement for the paper "Funk, cosine, and sine transforms
on Stiefel and Grassmann manifolds, II" by Boris Rubin.
Abstract: We investigate analytic continuation of the matrix cosine and
sine transforms introduced in Part I and depending on a complex parameter
$\a$. It is shown that the cosine transform corresponding to $\a=0$ is a
constant multiple of the Funk-Radon transform in integral geometry for
a pair of Stiefel (or Grassmann) manifolds. The same case for the sine
transform gives the identity operator. These results and the relevant
composition formula for the cosine transforms were established in Part
I in the sense of distributions. Now we have them pointwise. Some new
problems are formulated.
Archive classification: math.FA
Remarks: 18 pages
Submitted from: borisr(a)math.lsu.edu
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1103.1161
or
http://arXiv.org/abs/1103.1161
This is an announcement for the paper "A note on Gram-Schmidt's algorithm
for a general angle" by Tord Sj\"odin.
Abstract: The Gram-Schmidt algorithm produces a pairwise orthogonal set
from a linearly independent set of vectors in an inner product vector
space V. We give a linear algorithm that constructs vectors with the
same span and which have pairwise the same prescribed angle or distance,
in all cases where this is possible. Finally, we prove an asymptotic
property in the case of an infinite dimensional space V.
Archive classification: math.FA math.GM math.MG
Mathematics Subject Classification: Primary 15 A 03, Secondary 15 A 63,
46 C 05
Remarks: 8 pages
Submitted from: tord.sjodin(a)math.umu.se
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1103.1310
or
http://arXiv.org/abs/1103.1310
This is an announcement for the paper "The $p$-Daugavet property for
function spaces" by Enrique A. Sanchez Perez and Dirk Werner.
Abstract: A natural extension of the Daugavet property for $p$-convex
Banach function spaces and related classes is analysed. As an application,
we extend the arguments given in the setting of the Daugavet property
to show that no reflexive space falls into this class.
Archive classification: math.FA
Mathematics Subject Classification: Primary 46B04, secondary 46B25
Submitted from: werner(a)math.fu-berlin.de
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1103.1284
or
http://arXiv.org/abs/1103.1284
This is an announcement for the paper "Lushness, numerical index 1 and
the Daugavet property in rearrangement invariant spaces" by Vladimir
Kadets, Miguel Martin, Javier Meri, and Dirk Werner.
Abstract: We show that for spaces with 1-unconditional bases lushness, the
alternative Daugavet property and numerical index~1 are equivalent. In
the class of rearrangement invariant (r.i.)\ sequence spaces the
only examples of spaces with these properties are $c_0$, $\ell_1$ and
$\ell_\infty$. The only lush r.i.\ separable function space on $[0,1]$
is $L_1[0,1]$; the same space is the only r.i.\ separable function space
on $[0,1]$ with the Daugavet property over the reals.
Archive classification: math.FA
Mathematics Subject Classification: Primary 46B04. Secondary 46E30
Submitted from: werner(a)math.fu-berlin.de
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1103.1282
or
http://arXiv.org/abs/1103.1282
This is an announcement for the paper "Auerbach bases and minimal volume
sufficient enlargements" by Mikhail I. Ostrovskii.
Abstract: Let $B_Y$ denote the unit ball of a normed linear space $Y$. A
symmetric, bounded, closed, convex set $A$ in a finite dimensional normed
linear space $X$ is called a {\it sufficient enlargement} for $X$ if,
for an arbitrary isometric embedding of $X$ into a Banach space $Y$,
there exists a linear projection $P:Y\to X$ such that $P(B_Y)\subset
A$. Each finite dimensional normed space has a minimal-volume sufficient
enlargement which is a parallelepiped, some spaces have ``exotic''
minimal-volume sufficient enlargements. The main result of the paper is
a characterization of spaces having ``exotic'' minimal-volume sufficient
enlargements in terms of Auerbach bases.
Archive classification: math.FA
Mathematics Subject Classification: 46B07 (primary), 52A21, 46B15
(secondary)
Submitted from: ostrovsm(a)stjohns.edu
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1103.0997
or
http://arXiv.org/abs/1103.0997
This is an announcement for the paper "Embeddability of locally finite
metric spaces into Banach spaces is finitely determined" by Mikhail
I. Ostrovskii.
Abstract: The main purpose of the paper is to prove the following results:
Let $A$ be a locally finite metric space whose finite subsets admit uniformly
bilipschitz embeddings into a Banach space $X$. Then $A$ admits a
bilipschitz embedding into $X$.
Let $A$ be a locally finite metric space whose finite subsets admit uniformly
coarse embeddings into a Banach space $X$. Then $A$ admits a coarse
embedding into $X$.
These results generalize previously known results of the same type due to
Brown-Guentner (2005), Baudier (2007), Baudier-Lancien (2008), and the
author (2006, 2009).
One of the main steps in the proof is: each locally finite subset of an
ultraproduct $X^\mathcal{U}$ admits a bilipschitz embedding into $X$. We
explain how this result can be used to prove analogues of the main
results for other classes of embeddings.
Archive classification: math.FA
Submitted from: ostrovsm(a)stjohns.edu
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1103.0748
or
http://arXiv.org/abs/1103.0748
This is an announcement for the paper "Geometry of log-concave
ensembles of random matrices and approximate reconstruction" by
Radoslaw Adamczak, Rafal Latala, Alexander E. Litvak, Alain Pajor,
and Nicole Tomczak-Jaegermann.
Abstract: We study the Restricted Isometry Property of a random matrix
$\Gamma$ with independent isotropic log-concave rows. To this end, we
introduce a parameter $\Gamma_{k,m}$ that controls uniformly the operator
norm of sub-matrices with $k$ rows and $m$ columns. This parameter is
estimated by means of new tail estimates of order statistics and deviation
inequalities for norms of projections of an isotropic log-concave vector.
Archive classification: math.PR math.FA math.MG
Mathematics Subject Classification: Primary 52A23, 46B06, 46B09, 60E15
Secondary 15B52, 94B75
Submitted from: radamcz(a)mimuw.edu.pl
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1103.0401
or
http://arXiv.org/abs/1103.0401
This is an announcement for the paper "On the structure of non dentable
subsets of C({\omega}^{\omega}^k)" by Pericles D Pavlakos and Minos
Petrakis.
Abstract: It is shown that there is no K closed convex bounded
non-dentable subset of C({\omega}^{\omega} ^k) such that on the subsets
of K the PCP and the RNP are equivalent properties. Then applying
Schachermayer-Rosenthal theorem, we conclude that every non-dentable K
contains non-dentable subset L so that on L the weak topology coincides
with the norm one. It follows from known results that the RNP and the
KMP are equivalent properties on the subsets of C({\omega}^{\omega} ^k).
Archive classification: math.FA
Remarks: 18 pages,accepted in Studia Mathematica
Submitted from: minos(a)science.tuc.gr
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1103.0366
or
http://arXiv.org/abs/1103.0366
This is an announcement for the paper "A disintegration theorem" by
Marek Kosiek and Krzysztof Rudol.
Abstract: A new approach to disintegration of measures is presented,
allowing one to drop the usually taken separability assumption. The main
tool is a result on fibers in the spectrum of algebra of essentially
bounded functions established recently by the first-named author.
Archive classification: math.FA
Mathematics Subject Classification: Primary: 28A50, Secondary: 46J10
Remarks: 3 pages
Submitted from: Marek.Kosiek(a)im.uj.edu.pl
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1103.0255
or
http://arXiv.org/abs/1103.0255