This is an announcement for the paper "The Kalton-Lancien theorem
revisited: Maximal regularity does not extrapolate" by Stephan Fackler.
Abstract: We give a new more explicit proof of a result by Kalton &
Lancien stating that on each Banach space with an unconditional basis not
isomorphic to a Hilbert space there exists a generator of a holomorphic
semigroup which does not have maximal regularity. In particular, we show
that there always exists a Schauder basis (f_m) such that the generator
is a Schauder multiplier associated to the sequence (2^m). Moreover,
we show that maximal regularity does not extrapolate: we construct
consistent holomorphic semigroups (T_p(t)) on L^p for p in (1, \infty)
which have maximal regularity if and only if p = 2. These assertions
were both open problems. Our approach is completely different than the
one of Kalton & Lancien. We use the characterization of maximal regularity
by R-sectoriality for our construction.
Archive classification: math.FA math.AP
Mathematics Subject Classification: 35K90, 47D06 (Primary) 46B15
(Secondary)
Remarks: 16 pages
Submitted from: stephan.fackler(a)uni-ulm.de
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1210.4333
or
http://arXiv.org/abs/1210.4333
This is an announcement for the paper "Szlenk and $w^\ast$-dentability
indices of the Banach spaces $C([0,\alpha])$" by Philip A.H. Brooker.
Abstract: Let $\alpha$ be an infinite ordinal and $\gamma$ the
unique ordinal satisfying $\omega^{\omega^\gamma}\leq \alpha
< \omega^{\omega^{\gamma+1}}$. We show that the Banach space
$C([0,\,\alpha])$ of all continuous scalar-valued functions on the
compact ordinal interval $[0,\,\alpha]$ has Szlenk index equal
to $\omega^{\gamma+1}$ and $w^\ast$-dentability index equal to
$\omega^{1+\gamma+1}$.
Archive classification: math.FA
Mathematics Subject Classification: 46B03, 46B20
Submitted from: philip.a.h.brooker(a)gmail.com
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1210.3696
or
http://arXiv.org/abs/1210.3696
This is an announcement for the paper "On Pietsch measures for summing
operators and dominated polynomials" by Geraldo Botelho, Daniel
Pellegrino, and Pilar Rueda.
Abstract: We relate the injectivity of the canonical map from $C(B_{E'})$
to $L_p(\mu)$, where $\mu$ is a regular Borel probability measure on
the closed unit ball $B_{E'}$ of the dual $E'$ of a Banach space $E$
endowed with the weak* topology, to the existence of injective $p$-summing
linear operators/$p$-dominated homogeneous polynomials defined on $E$
having $\mu$ as a Pietsch measure. As an application we fill the gap in
the proofs of some results of concerning Pietsch-type factorization of
dominated polynomials.
Archive classification: math.FA
Mathematics Subject Classification: 28C15, 46G25, 47B10, 47L22
Remarks: 13 pages
Submitted from: pilar.rueda(a)uv.es
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1210.3332
or
http://arXiv.org/abs/1210.3332
This is an announcement for the paper "Function spaces not containing
$\ell_{1}$" by S.A. Argyros, A. Manoussakis, and M. Petrakis.
Abstract: For $\Omega$ bounded and open subset of $\mathbb{R}^{d_{0}}$
and $X$ a reflexive Banach space with $1$-symmetric basis, the function
space $JF_{X}(\Omega)$ is defined. This class of spaces includes the
classical James function space. Every member of this class is separable
and has non-separable dual. We provide a proof of topological nature that
$JF_{X}(\Omega)$ does not contain an isomorphic copy of $\ell_{1}$. We
also investigate the structure of these spaces and their duals.
Archive classification: math.FA
Mathematics Subject Classification: 46B10
Citation: Israel Journal of Mathematics 135 (2003), 29-81
Submitted from: amanousakis(a)isc.tuc.gr
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1210.2379
or
http://arXiv.org/abs/1210.2379
This is an announcement for the paper "Lorentz spaces with variable
exponents" by Henning Kempka and Jan Vybiral.
Abstract: We introduce Lorentz spaces $L_{p(\cdot),q}(\R^n)$ and
$L_{p(\cdot),q(\cdot)}(\R^n)$ with variable exponents. We prove several
basic properties of these spaces including embeddings and the identity
$L_{p(\cdot),p(\cdot)}(\R^n)=L_{p(\cdot)}(\R^n)$. We also show that
these spaces arise through real interpolation between $L_{\p}(\R^n)$
and $L_\infty(\R^n)$. Furthermore, we answer in a negative way the
question posed in \cite{DHN} whether the Marcinkiewicz interpolation
theorem holds in the frame of Lebesgue spaces with variable integrability.
Archive classification: math.FA
Submitted from: henning.kempka(a)uni-jena.de
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1210.1738
or
http://arXiv.org/abs/1210.1738
This is an announcement for the paper "A Banach rearrangement norm
characterization for tail behavior of measurable functions (random
variables)" by E.Ostrovsky and L.Sirota.
Abstract: We construct a Banach rearrangement invariant norm on the
measurable space for which the finiteness of this norm for measurable
function (random variable) is equivalent to suitable tail (heavy tail
and light tail) behavior.
We investigate also a conjugate to offered spaces and obtain some
embedding theorems. Possible applications: Functional Analysis (for
instance, interpolation of operators), Integral Equations, Probability
Theory and Statistics (tail estimations for random variables).
Archive classification: math.FA math.PR
Submitted from: leos(a)post.sce.ac.il
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1210.1168
or
http://arXiv.org/abs/1210.1168
This is an announcement for the paper "On convergence with respect to
an ideal and a family of matrices" by Jan-David Hardtke.
Abstract: Recently P. Das, S. Dutta and E. Savas introduced and
studied the notions of strong $A^I$-summability with respect to an
Orlicz function $F$ and $A^I$-statistical convergence, where $A$ is a
non-negative regular matrix and $I$ is an ideal on the set of natural
numbers. In this note, we will generalise these notions by replacing $A$
with a family of matrices and $F$ with a family of Orlicz functions or
moduli and study the thus obtained convergence methods. We will also
give an application in Banach space theory, presenting a generalisation
of Simons' $\sup$-$\limsup$-theorem to the newly introduced convergence
methods (for the case that the filter generated by the ideal $I$ has a
countable base), continuing the author's previous work.
Archive classification: math.FA
Mathematics Subject Classification: 40C05, 40C99, 46B20
Remarks: 32 pages
Submitted from: hardtke(a)math.fu-berlin.de
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1210.1350
or
http://arXiv.org/abs/1210.1350
This is an announcement for the paper "Non-separable tree-like Banach
spaces and Rosenthal's $\ell_1$-theorem " by Costas Poulios.
Abstract: We introduce and investigate a class of non-separable tree-like
Banach spaces. As a consequence, we prove that we can not achieve a
satisfactory extension of Rosenthal's $\ell_1$-theorem to spaces of the
type $\ell_1(\kappa)$, for $\kappa$ an uncountable cardinal.
Archive classification: math.FA
Mathematics Subject Classification: 46B25, 46B26
Submitted from: k-poulios(a)math.uoa.gr
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1210.0792
or
http://arXiv.org/abs/1210.0792
This is an announcement for the paper "Quantitative nonlinear embeddings
into Lebesgue sequence spaces" by Florent P. Baudier.
Abstract: In this paper coarse, uniform and strong embeddings of metric
spaces into Lebesgue sequence spaces are studied in their quantitative
aspects. In particular, strong deformation gaps are obtained when
embedding strongly a Hilbert space into $\ell_p$ for $0<p< 2$ as well as
new insights on the nonlinear geometry of the spaces $L_p$ and $\ell_p$
for $0<p<1$. The exact $\ell_q$-compression of $\ell_p$-spaces is
computed. Finally the coarse deformation of metric spaces with property
A and amenable groups is investigated.
Archive classification: math.FA math.MG
Mathematics Subject Classification: 46B20, 46B85, 46T99, 20F65
Submitted from: florent(a)math.tamu.edu
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1210.0588
or
http://arXiv.org/abs/1210.0588
This is an announcement for the paper "On approximations by projections
of polytopes with few facets" by Alexander E. Litvak, Mark Rudelson,
and Nicole Tomczak-Jaegermann.
Abstract: We provide an affirmative answer to a problem posed by
Barvinok and Veomett, showing that in general an n-dimensional convex
body cannot be approximated by a projection of a section of a simplex
of a sub-exponential dimension. Moreover, we establish a lower bound of
the Banach-Mazur distance between n-dimensional projections of sections
of an N-dimensional simplex and a certain convex symmetric body, which
is sharp up to a logarithmic factor for all N>n.
Archive classification: math.FA math.MG
Mathematics Subject Classification: Primary: 52A23, 52A27, Secondary:
52B55, 46B09
Remarks: 22 pages
Submitted from: rudelson(a)umich.edu
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1209.6281
or
http://arXiv.org/abs/1209.6281