This is an announcement for the paper "A hereditarily indecomposable
L_\infty-space that solves the scalar-plus-compact problem" by Spiros
A Argyros and Richard G Haydon.
Abstract: We construct a hereditarily indecomposable Banach space with
dual isomorphic to $\ell_1$. Every bounded linear operator on this space
has the form $\lambda I+K$ with $\lambda$ a scalar and $K$ compact.
Archive classification: math.FA
Mathematics Subject Classification: 46B45
The source file(s), BD.tex: 14514 bytes Background.tex: 8660 bytes
ConcRem.tex.bak: 13883 bytes Constr.tex: 14452 bytes HIDuals.tex: 12435
bytes Intro.tex: 3383 bytes Operators.tex: 9684 bytes RIS.tex: 22263
bytes ScalarPlusCompact.tex: 8259 bytes ellOneExact.tex: 15439 bytes,
is(are) stored in gzipped form as 0903.3921.tar.gz with size 39kb. The
corresponding postcript file has gzipped size 191kb.
Submitted from: richard.haydon(a)bnc.ox.ac.uk
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This is an announcement for the paper "Linear operators with compact
supports, probability measures and Milyutin maps" by Vesko Valov.
Abstract: The notion of a regular operator with compact supports between
function spaces is introduced. On that base we obtain a characterization
of absolute extensors for zero-dimensional spaces in terms of regular
extension operators having compact supports. Milyutin maps are also
considered and it is established that some topological properties, like
paracompactness, metrizability and k-metrizability, are preserved under
Milyutin maps.
Archive classification: math.GN math.FA
Mathematics Subject Classification: 28A33; 54C10
Remarks: 26 pages
The source file(s), Milutin.TEX: 91700 bytes, is(are) stored in gzipped
form as 0903.3435.gz with size 25kb. The corresponding postcript file
has gzipped size 141kb.
Submitted from: veskov(a)nipissingu.ca
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/0903.3435
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This is an announcement for the paper "On generalizations of Gowers
norms and their geometry" by Hamed Hatami.
Abstract: Motivated by the definition of the Gowers uniformity norms,
we introduce and study a wide class of norms. Our aim is to establish
them as a natural generalization of the $L_p$ norms. We shall prove
that these normed spaces share many of the nice properties of the $L_p$
spaces. Some examples of these norms are $L_p$ norms, trace norms $S_p$
when $p$ is an even integer, and Gowers uniformity norms.
Every such norm is defined through a pair of weighted hypergraphs. In regard
to a question of Laszlo Lovasz, we prove several results in the direction
of characterizing all hypergraph pairs that correspond to norms.
Archive classification: math.CO math.FA
Mathematics Subject Classification: 46B20, 46E30, 05D99
Remarks: 29 pages
The source file(s), arxiv/ProductNorm17.bbl: 3969 bytes
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/0903.3237
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This is an announcement for the paper "Kolmogorov compactness criterion
in variable exponent Lebesgue spaces" by Humberto Rafeiro.
Abstract: The well-known Kolmogorov compactness criterion
is extended to the case of variable exponent Lebesgue spaces
$L^{p(\cdot)}(\overline{\Omega})$, where $\Omega$ is a bounded open set in
$\mathbb R^n$ and $p(\cdot)$ satisfies some ``standard'' conditions. Our
final result should be called Kolmogorov-Tulajkov Sudakov compactness
criterion, since it includes the case $p_-=1$ and requires only the
``uniform'' condition.
Archive classification: math.FA
Mathematics Subject Classification: 46B50, 46E30
Remarks: 8 pages
The source file(s), kolmogorov_18_03_2009.tex: 23807 bytes, is(are)
stored in gzipped form as 0903.3214.gz with size 8kb. The corresponding
postcript file has gzipped size 76kb.
Submitted from: hrafeiro(a)ualg.pt
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http://front.math.ucdavis.edu/0903.3214
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Workshop in Analysis and Probability
Department of Mathematics
Texas A&M University
Summer 2009
The Summer 2009 Workshop in Analysis and Probability at Texas A&M
University will be in session from July 7 until August 13. For
information about the Workshop, consult the Workshop Home Page, URL
http://www.math.tamu.edu/research/workshops/linanalysis/
The Informal Regional Functional Analysis Seminar (SUMIRFAS) will be held
August 7-9.
Rafal Latala, Assaf Naor, and Grigoris Paouris (chair) are
organizing a Concentration Week on "Probability in Asymptotic Geometry"
for the week of
July 20-24. This Concentration Week will focus on high dimensional
phenomena
concerning convex bodies, random polytopes, and random matrices.
These topics lie in the intersection of probability, analysis, geometry,
and combinatorics. The goal is to expose the huge variety of techniques
used in the study of these objects
and to explore the connections between them.
Marius Junge, Jesse Peterson, and Gilles Pisier (chair) are organizing a
Concentration Week on "Operator Spaces and Approximation Properties of
Discrete Groups" for the week of August 3-7. Particular emphasis will be
taken to tie together recent results from the theory of von Neumann
algebras with operator space ideas. The intention
is to provide a background for common points of interest from different
perspectives through courses on operator spaces and Dirichlet forms in
von Neumann algebras. The intention of this concentration week is to
attract attention of younger researchers and students to
these new openings
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
Larson <larson(a)math.tamu.edu>, Gilles Pisier <pisier(a)math.tamu.edu>, or
Joel Zinn <jzinn(a)math.tamu.edu>.
For information about the Concentration Week "Probability in Asymptotic
Geometry" contact Grigoris Paouris <grigoris(a)math.tamu.edu>.
For information about the Concentration Week on "Operator Spaces and
Approximation Properties of Discrete Groups", contact Gilles Pisier
<pisier(a)math.tamu.edu>.
This is an announcement for the paper "Hausdorff measures and functions
of bounded quadratic variation" by D.Apatsidis, S.A.Argyros, and
V.Kanellopoulos.
Abstract: To each function $f$ in the space $V_2$ we associate a Hausdorff
measure $\mu_f$. We show that the map $f\to\mu_f$ is locally Lipschitz
and onto the positive cone of $\mathcal{M}[0,1]$. We use the measures
$\{\mu_f:f\in V_2\}$ to determine the structure of the subspaces of
$V_2^0$ which either contain $c_0$ or the square stopping time space
$S^2$.
Archive classification: math.FA
Mathematics Subject Classification: 28A78, 46B20, 46B26
Remarks: 36 pages
The source file(s), haus_quad2.tex: 141123 bytes, is(are) stored in
gzipped form as 0903.2809.gz with size 38kb. The corresponding postcript
file has gzipped size 219kb.
Submitted from: sargyros(a)math.ntua.gr
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This is an announcement for the paper "On the numerical index of real
$L_p(\mu)$-spaces" by Miguel Martin, Javier Meri, and Mikhail Popov.
Abstract: We give a lower bound for the numerical index of the
real space $L_p(\mu)$ showing, in particular, that it is non-zero
for $p\neq 2$. In other words, it is shown that for every bounded
linear operator $T$ on the real space $L_p(\mu)$, one has $$
\sup\left\{\Bigl|\int |x|^{p-1}\sign(x)\,T x\ d\mu \Bigr|\ : \
x\in L_p(\mu),\,\|x\|=1\right\} \geq \frac{M_p}{8\e}\|T\| $$ where
$\displaystyle M_p=\max_{t\in[0,1]}\frac{|t^{p-1}-t|}{1+t^p}>0$ for every
$p\neq 2$. It is also shown that for every bounded linear operator $T$
on the real space $L_p(\mu)$, one has $$ \sup\left\{\int |x|^{p-1}|Tx|\
d\mu \ : \ x\in L_p(\mu),\,\|x\|=1\right\} \geq \frac{1}{2\e}\|T\|. $$
Archive classification: math.FA math.OA
Mathematics Subject Classification: 46B04, 46E30, 47A12
The source file(s), MartinMeriPopov.tex: 21471 bytes, is(are) stored in
gzipped form as 0903.2704.gz with size 7kb. The corresponding postcript
file has gzipped size 74kb.
Submitted from: mmartins(a)ugr.es
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This is an announcement for the paper "Zero subspaces of polynomials on
l1(Gamma)" by Antonio Aviles and Stevo Todorcevic.
Abstract: We provide two examples of complex homogeneous quadratic
polynomials P on Banach spaces of the form l_1(I). The first polynomial
P has both separable and nonseparable maximal zero subspaces. The second
polynomial P has the property that while the index-set I is not countable,
all zero subspaces of P are separable.
Archive classification: math.FA math.LO
Mathematics Subject Classification: 46B26, 47H60
Citation: J. Math. Anal. Appl. 350, No. 2, 427-435 (2009)
Remarks: Published in special issue dedicated to Isaac Namioka
The source file(s), polynomials3.tex: 39718 bytes, is(are) stored in
gzipped form as 0903.2374.gz with size 13kb. The corresponding postcript
file has gzipped size 89kb.
Submitted from: avileslo(a)um.es
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This is an announcement for the paper "J-class operators and
hypercyclicity" by George Costakis and Antonios Manoussos.
Abstract: The purpose of the present work is to treat a new notion
related to linear dynamics, which can be viewed as a ``localization"
of the notion of hypercyclicity. In particular, let $T$ be a bounded
linear operator acting on a Banach space $X$ and let $x$ be a non-zero
vector in $X$ such that for every open neighborhood $U\subset X$ of $x$
and every non-empty open set $V\subset X$ there exists a positive integer
$n$ such that $T^{n}U\cap V\neq\emptyset$. In this case $T$ will be called
a $J$-class operator. We investigate the class of operators satisfying
the above property and provide various examples. It is worthwhile to
mention that many results from the theory of hypercyclic operators
have their analogues in this setting. For example we establish results
related to the Bourdon-Feldman theorem and we characterize the $J$-class
weighted shifts. We would also like to stress that even non-separable
Banach spaces which do not support topologically transitive operators,
as for example $l^{\infty}(\mathbb{N})$, do admit $J$-class operators.
Archive classification: math.FA math.DS
Mathematics Subject Classification: 47A16 (primary); 37B99, 54H20
(secondary)
Remarks: 21 pages
The source file(s), manoussos_jclass.tex: 62003 bytes, is(are) stored in
gzipped form as 0704.3354.gz with size 16kb. The corresponding postcript
file has gzipped size 116kb.
Submitted from: aman(a)math.uoc.gr
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http://front.math.ucdavis.edu/0704.3354
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This is an announcement for the paper "Properties of representations of
operators acting between spaces of vector-valued functions" by Delio
Mugnolo and Robin Nittka.
Abstract: A well-known result going back to the 1930s states that
all bounded linear operators mapping scalar-valued $L^1$-spaces into
$L^\infty$-spaces are kernel operators and that in fact this relation
induces an isometric isomorphism between those operators and the space
of all bounded kernels. We extend this result to the case of spaces of
vector-valued functions.
A recent result due to Arendt and Thomaschewski states that the local
operators acting on $L^p$-spaces of functions with values in separable
spaces are precisely the multiplication operators. We extend this result
to non-separable dual spaces. Moreover, we relate positivity and other
order properties of the operators to corresponding properties of the
representations.
Archive classification: math.FA
Mathematics Subject Classification: 46G10, 47B34, 46M10, 47B65
Remarks: 13 pages
The source file(s), dunfordpettis.bbl: 5993 bytes
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/0903.2038
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