This is an announcement for the paper "Free spaces over some proper
metric spaces" by Aude Dalet.
Abstract: We prove that the Lipschitz-free space over a countable proper
metric space and over a proper ultrametric space is isometric to a dual
space and has the metric approximation property.
Archive classification: math.FA
Mathematics Subject Classification: 46B10, 46B28
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/1404.3939
or
http://arXiv.org/abs/1404.3939
This is an announcement for the paper "On the R-boundedness of stochastic
convolution operators" by Jan van Neerven, Mark Veraar, and Lutz Weis.
Abstract: The $R$-boundedness of certain families of vector-valued
stochastic convolution operators with scalar-valued square integrable
kernels is the key ingredient in the recent proof of stochastic maximal
$L^p$-regularity, $2<p<\infty$, for certain classes of sectorial operators
acting on spaces $X=L^q(\mu)$, $2\le q<\infty$. This paper presents a
systematic study of $R$-boundedness of such families. Our main result
generalises the afore-mentioned $R$-boundedness result to a larger class
of Banach lattices $X$ and relates it to the $\ell^{1}$-boundedness
of an associated class of deterministic convolution operators. We also
establish an intimate relationship between the $\ell^{1}$-boundedness
of these operators and the boundedness of the $X$-valued maximal
function. This analysis leads, quite surprisingly, to an example showing
that $R$-boundedness of stochastic convolution operators fails in certain
UMD Banach lattices with type $2$.
Archive classification: math.FA math.PR
Mathematics Subject Classification: Primary: 60H15, Secondary: 42B25,
46B09, 46E30, 60H05
Submitted from: m.c.veraar(a)tudelft.nl
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1404.3353
or
http://arXiv.org/abs/1404.3353
This is an announcement for the paper "An introduction to Nigel Kalton's
work on differentials of complex interpolation processes for Kothe spaces"
by Michael Cwikel, Mario Milman and Richard Rochberg.
Abstract: This paper contains no new results. It is intended to be merely
a brief introduction to the long paper:
N. J. Kalton, Differentials of complex interpolation processes
for Kothe
function spaces. Trans. Amer. Math. Soc. 333 (1992), no. 2, 479--529.
and to mention some possible directions for applying the powerful
methods
developed in Kalton's paper for further future research. The reader
should also be aware of other perspectives in other commentaries on
Kalton's paper, which appear in other sources to which we refer.
Archive classification: math.FA
Mathematics Subject Classification: 46B70 (Primary), 42B20, 42B30, 42B35,
46B42 (Secondary)
Remarks: 12 pages
Submitted from: mcwikel(a)math.technion.ac.il
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1404.2893
or
http://arXiv.org/abs/1404.2893
This is an announcement for the paper "Absolutely summing multilinear
operators on $\ell_p$ spaces" by O. Blasco, G. Botelho, D, Pellegrino,
and P. Rueda.
Abstract: We prove new summability properties for multilinear operators on
$\ell_p$ spaces. An important tool for this task is a better understanding
of the interplay between almost summing and absolutely summing multilinear
operators.
Archive classification: math.FA
Submitted from: pellegrino(a)pq.cnpq.br
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1404.1322
or
http://arXiv.org/abs/1404.1322
This is an announcement for the paper "On improvement of the concavity
of convex measures" by Arnaud Marsiglietti.
Abstract: We prove that a general class of measures, which includes
$\log$-concave measures, are $\frac{1}{n}$-concave in the terminology
of Borell under additional assumptions on the measure or on the sets,
such as symmetries. This generalizes results of Gardner and Zvavitch.
Archive classification: math.FA
Submitted from: arnaud.marsiglietti(a)univ-mlv.fr
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1403.7643
or
http://arXiv.org/abs/1403.7643
This is an announcement for the paper "A note on a
Bohnenblust-Hille-Helson type inequality" by Daniel Carando, Andreas
Defant, and Pablo Sevilla-Peris.
Abstract: We give a variant of the Bohenblust-Hille inequality which,
for certain families of polynomials, leads to constants with polynomial
growth in the degree.
Archive classification: math.FA
Submitted from: psevilla(a)mat.upv.es
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1403.7033
or
http://arXiv.org/abs/1403.7033
This is an announcement for the paper "Integral representation of linear
functionals on function spaces" by Mehdi Ghasemi.
Abstract: Let $A$ be a vector space of real valued functions
on a non-empty set $X$ and $L:A\rightarrow\mathbb{R}$ a linear
functional. Given a $\sigma$-algebra $\mathcal{A}$, of subsets of $X$,
we present a necessary condition for $L$ to be representable as an
integral with respect to a measure $\mu$ on $X$ such that elements
of $\mathcal{A}$ are $\mu$-measurable. This general result then is
applied to the case where $X$ carries a topological structure and $A$
is a family of continuous functions and naturally $\mathcal{A}$ is the
Borel structure of $X$. As an application, short solutions for the
full and truncated $K$-moment problem are presented. An analogue of
Riesz-Markov-Kakutani representation theorem is given where $C_{c}(X)$
is replaced with whole $C(X)$. Then we consider the case where $A$
only consists of bounded functions and hence is equipped with $\sup$-norm.
Archive classification: math.FA
Mathematics Subject Classification: 47A57, 28C05, 28E99
Submitted from: mehdi.ghasemi(a)usask.ca
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1403.6956
or
http://arXiv.org/abs/1403.6956
This is an announcement for the paper "Products of Lipschitz-free spaces
and applications" by Pedro Levit Kaufmann.
Abstract: We show that, given a Banach space $X$, the Lipschitz-free
space over $X$, denoted by $\mathcal{F}(X)$, is isomorphic to
$(\sum_{n=1}^\infty \mathcal{F}(X))_{\ell_1}$. Some applications are
presented, including a non-linear version of Pe\l czy\'ski's decomposition
method for Lipschitz-free spaces and the identification up to isomorphism
between $\mathcal{F}(\mathbb{R}^n)$ and the Lipschitz-free space over
any compact metric space which is locally bi-Lipschitz embeddable into
$\mathbb{R}^n$ and which contains a subset that is Lipschitz equivalent
to the unit ball of $\mathbb{R}^n$. We also show that $\mathcal{F}(M)$
is isomorphic to $\mathcal{F}(c_0)$ for all separable metric spaces $M$
which are absolute Lipschitz retracts and contain a subset which is
Lipschitz equivalent to the unit ball of $c_0$. This class contains
all $C(K)$ spaces with $K$ infinite compact metric (Dutrieux and
Ferenczi had already proved that $\mathcal{F}(C(K))$ is isomorphic to
$\mathcal{F}(c_0)$ for those $K$ using a different method). Finally we
study Lipschitz-free spaces over certain unions and quotients of metric
spaces, extending a result by Godard.
Archive classification: math.FA
Mathematics Subject Classification: Primary 46B20, Secondary 46T99
Remarks: 17 pages, 1 figure
Submitted from: pkaufmann(a)math.jussieu.fr
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1403.6605
or
http://arXiv.org/abs/1403.6605
This is an announcement for the paper "On a conjecture of Pisier on the
analyticity of semigroups" by Cedric Arhancet.
Abstract: We show that the analyticity of some semigroups $(T_t)_{t \geq
0}$ of contractive Fourier multipliers on $L^p$-spaces of compact abelian
groups is preserved by the tensorisation of the identity operator of
a Banach space for a large class of K-convex Banach spaces, answering
partially a conjecture of Pisier. We also give versions of this result
for some semigroups of Schur multipliers and Fourier multipliers on
noncommutative $L^p$-spaces. Finally, we give a precise description of
semigroups of Schur multipliers to which the result of this paper can
be applied.
Archive classification: math.FA
Remarks: 10 pages; comments are welcome
Submitted from: cedric.arhancet(a)univ-fcomte.fr
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1403.6737
or
http://arXiv.org/abs/1403.6737
This is an announcement for the paper "Bounded holomorphic functions
attaining their norms in the bidual" by Daniel Carando and Martin
Mazzitelli.
Abstract: Under certain hypotheses on the Banach space $X$, we prove
that the set of analytic functions in $\mathcal{A}_u(X)$ (the algebra
of all holomorphic and uniformly continuous functions in the ball
of $X$) whose Aron-Berner extensions attain their norms, is dense in
$\mathcal{A}_u(X)$. The result holds also for functions with values in a
dual space or in a Banach space with the so-called property $(\beta)$. For
this, we establish first a Lindenstrauss type theorem for continuous
polynomials. We also present some counterexamples for the Bishop-Phelps
theorem in the analytic and polynomial cases where our results apply.
Archive classification: math.FA
Submitted from: mmazzite(a)dm.uba.ar
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1403.6431
or
http://arXiv.org/abs/1403.6431