This is an announcement for the paper "Rethinking Polyhedrality for
Lindenstrauss Spaces" by Emanuele Casini, Enrico Miglierina, and Lukasz
Piasecki.
Abstract:
A recent example by the authors (see arXiv:1503.09088 [math.FA]) shows
that an old result of Zippin about the existence of an isometric copy of
$c$ in a separable Lindenstrauss space is incorrect. The same example
proves that some characterizations of polyhedral Lindenstrauss spaces,
based on the result of Zippin, are false. The main result of the present
paper provides a new characterization of polyhedrality for the preduals
of $\ell_{1}$ and gives a correct proof for one of the older. Indeed,
we prove that for a space $X$ such that $X^{*}=\ell_{1}$ the following
properties are equivalent:
(1) $X$ is a polyhedral space; (2) $X$ does not contain an isometric
copy of $c$; (3) $\sup\left\{ x^{*}(x)\,:\,
x^{*}\in\mathrm{ext}\left(B_{X^{*}}\right)\setminus D(x)\right\}
<1$ for each $x\in S_{X}$, where $D(x)=\left\{ x^{*}\in
S_{X^{*}}:x^{*}(x)=1\right\}$.
By known theory, from our result follows that a generic Lindenstrauss
space is polyhedral if and only if it does not contain an isometric copy
of $c$. Moreover, a correct version of the result of Zippin is derived
as a corollary of the main result.
Archive classification: math.FA
Mathematics Subject Classification: 46B04, 46B20, 46B25
Submitted from: enrico.miglierina(a)unicatt.it
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1506.08559
or
http://arXiv.org/abs/1506.08559
This is an announcement for the paper "Estimates for vector-valued
holomorphic functions and Littlewood-Paley-Stein theory" by Mark Veraar
and Lutz Weis.
Abstract:
In this paper we consider generalized square function norms of
holomorphic functions with values in a Banach space. One of the main
results is a characterization of embeddings of the form \[L^p(X)\subseteq
\gamma(X) \subseteq L^q(X),\] in terms of the type $p$ and cotype $q$
for the Banach space $X$. As an application we prove $L^p$-estimates
for vector-valued Littlewood-Paley-Stein $g$-functions and derive an
embedding result for real and complex interpolation spaces under type
and cotype conditions.
Archive classification: math.FA
Mathematics Subject Classification: Primary 46B09, Secondary: 42B25,
46B70, 46E40, 46B20, 47D07
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/1506.08013
or
http://arXiv.org/abs/1506.08013
This is an announcement for the paper "Equivalent norms with the property
$(\beta)$ of Rolewicz" by Stephen J. Dilworth, Denka Kutzarova, Gilles
Lancien and Lovasoa N. Randrianarivony.
Abstract:
We extend to the non separable setting many characterizations of the
Banach spaces admitting an equivalent norm with the property $(\beta)$
of Rolewicz. These characterizations involve in particular the Szlenk
index and asymptotically uniformly smooth or convex norms. This allows
to extend easily to the non separable case some recent results from the
non linear geometry of Banach spaces.
Archive classification: math.FA
Submitted from: gilles.lancien(a)univ-fcomte.fr
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1506.07978
or
http://arXiv.org/abs/1506.07978
This is an announcement for the paper "A short note on the Radon-Riesz
property for continuous Banach space valued functions" by Arne
Roggensack.
Abstract:
We present a generalization of the Radon-Riesz property to sequences of
continuous functions with values in uniformly convex and uniformly smooth
Banach spaces.
Archive classification: math.FA
Mathematics Subject Classification: Primary: 46B50, Secondary: 46B20
Submitted from: arne.roggensack(a)wias-berlin.de
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1506.07682
or
http://arXiv.org/abs/1506.07682
This is an announcement for the paper "The Kadec-Pe\l czynski theorem
in $L^p$, $1\le p<2$" by Istvan Berkes and Robert Tichy.
Abstract:
By a classical result of Kadec and Pe\l czynski (1962), every normalized
weakly null sequence in $L^p$, $p>2$ contains a subsequence equivalent
to the unit vector basis of $\ell^2$ or to the unit vector basis of
$\ell^p$. In this paper we investigate the case $1\le p<2$ and show
that a necessary and sufficient condition for the first alternative in
the Kadec-Pe\l czynski theorem is that the limit random measure $\mu$
of the sequence satisfies $\int_{\mathbb{R}} x^2 d\mu (x)\in L^{p/2}$.
Archive classification: math.FA
Submitted from: berkes(a)tugraz.at
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1506.07453
or
http://arXiv.org/abs/1506.07453
This is an announcement for the paper "Rademacher functions in Morrey
spaces" by Sergei V. Astashkin and Lech Maligranda.
Abstract:
The Rademacher functions are investigated in the Morrey spaces M(p,w) on
[0,1] for 1 \le p <\infty and weight w being a quasi-concave
function. They span l_2 space in M(p,w) if and only if the weight w is
smaller than the function log_2^{-1/2}(2/t) on (0,1). Moreover, if 1 <
p < \infty the Rademacher sunspace R_p is complemented in M(p,w) if and
only if it is isomorphic to l_2. However, the Rademacher subspace is
not complemented in M(1,w) for any quasi-concave weight w. In the last
part of the paper geometric structure of Rademacher subspaces in Morrey
spaces M(p,w) is described. It turns out that for any infinite-dimensional
subspace X of R_p the following alternative holds: either X is isomorphic
to l_2 or X contains a subspace which is isomorphic to c_0 and is
complemented in R_p.
Archive classification: math.FA
Mathematics Subject Classification: 46E30, 46B20, 46B42
Remarks: submitted
Submitted from: astash(a)samsu.ru
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1506.06862
or
http://arXiv.org/abs/1506.06862
This is an announcement for the paper "Domination spaces and factorization
of linear and multilinear summing operators" by E. Dahia, D. Achour,
P. Rueda and E. A. Sanchez Perez.
Abstract:
It is well known that not every summability property for non linear
operators leads to a factorization theorem. In this paper we undertake a
detailed study of factorization schemes for summing linear and nonlinear
operators. Our aim is to integrate under the same theory a wide family
of classes of mappings for which a Pietsch type factorization theorem
holds. We analyze the class of linear operators that are defined by a
summability inequality involving a homogeneous map. Our construction
includes the cases of absolutely $p$-summing linear operators,
$(p,\sigma)$-absolutely continuous linear operators, factorable
strongly $p$-summing multilinear operators, $(p_1,\ldots,p_n)$-dominated
multilinear operators and dominated $(p_1,\ldots, p_n;\sigma)$-continuous
multilinear operators.
Archive classification: math.FA
Submitted from: hajdahia(a)univ-msila.dz
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1506.06311
or
http://arXiv.org/abs/1506.06311
This is an announcement for the paper "Point-open games and productivity
of dense-separable property" by Jarno Talponen.
Abstract:
In this note we study the point-open topological games to analyze
the least upper bound for density of dense subsets of a topological
space. This way we may also analyze the behavior of such cardinal
invariants in taking products of spaces. Various related cardinal
equalities and inequalities are given. As an application we take a
look at Banach spaces with the property (CSP) which can be formulated
by stating that each weak-star dense linear subspace of the dual is
weak-star separable.
Archive classification: math.GN math.FA
Mathematics Subject Classification: 54A25, 54D70, 91A44, 46B26, 03E60
Submitted from: talponen(a)iki.fi
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1506.06080
or
http://arXiv.org/abs/1506.06080
This is an announcement for the paper "On uniformly bounded basis in
spaces of holomorphic functions" by Jean Bourgain.
Abstract:
The main result of the paper is the construction of explicit uniformly
bounded basis in the spaces of complex homogenous polynomials on the unit
ball of $C^3$, extending an earlier result of the author in the $C^2$ case
Archive classification: math.FA
Mathematics Subject Classification: Primary: 46E15, 32A99 Secondary: 42A56
Submitted from: bourgain(a)ias.edu
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1506.05694
or
http://arXiv.org/abs/1506.05694
This is an announcement for the paper "Uniform nonextendability from nets"
by Assaf Naor.
Abstract:
It is shown that there exist Banach spaces $X,Y$, a $1$-net
$\mathscr{N}$ of $X$ and a Lipschitz function $f:\mathscr{N}\to Y$
such that every $F:X\to Y$ that extends $f$ is not uniformly continuous.
Archive classification: math.MG math.FA
Submitted from: naor(a)math.princeton.edu
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1506.05391
or
http://arXiv.org/abs/1506.05391