This is an announcement for the paper "Sphere equivalence, Banach
expanders, and extrapolation" by Masato Mimura.
Abstract: We study the Banach spectral gap lambda_1(G;X,p) of finite
graphs G for pairs (X,p) of Banach spaces and exponents. We introduce the
notion of sphere equivalence between Banach spaces, and study behavior
of lambda_1(G;X,p) for fixed p in terms of this equivalence. We further
study behavior of lambda_1(G;X,p) for fixed X. As a byproduct, we show
a generalization of Matousek's extrapolation to that for any Banach
space which is sphere equivalent to a uniformly convex Banach space. We
as well prove that expanders are expanders with respects to (X,p) for
any X sphere equivalent to a uniformly curved Banach space and for any
finite p strictly bigger than 1.
Archive classification: math.GR math.CO math.FA math.MG
Remarks: 23 pages, no figure
Submitted from: mimura-mas(a)m.tohoku.ac.jp
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1310.4737
or
http://arXiv.org/abs/1310.4737
This is an announcement for the paper "Lyapunov theorem for q-concave
Banach spaces" by Anna Novikova.
Abstract: Generalization of Lyapunov convexity theorem is proved for
vector measure with values in Banach spaces with unconditional bases,
which are q-concave for some $q<\infty.$
Archive classification: math.FA
Mathematics Subject Classification: 46E30
Remarks: 7 pages
Submitted from: anna.novikova(a)weizmann.ac.il
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1310.4663
or
http://arXiv.org/abs/1310.4663
This is an announcement for the paper "Unbounded order convergence in
dual spaces" by Niushan Gao.
Abstract: A net $(x_\alpha)$ in a vector lattice $X$ is said to be
{unbounded order convergent} (or uo-convergent, for short) to $x\in X$
if the net $(\abs{x_\alpha-x}\wedge y)$ converges to $0$ in order for
all $y\in X_+$. In this paper, we study unbounded order convergence in
dual spaces of Banach lattices. Let $X$ be a Banach lattice. We prove that
every norm bounded uo-convergent net in $X^*$ is $w^*$-convergent iff $X$
has order continuous norm, and that every $w^*$-convergent net in $X^*$
is uo-convergent iff $X$ is atomic with order continuous norm. We also
characterize among $\sigma$-order complete Banach lattices the spaces in
whose dual space every simultaneously uo- and $w^*$-convergent sequence
converges weakly/in norm.
Archive classification: math.FA
Submitted from: niushan(a)ualberta.ca
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1310.4438
or
http://arXiv.org/abs/1310.4438
This is an announcement for the paper "p-summing multiplication operators,
dyadic Hardy Spaces and atomic decomposition" by Paul F.X. Muller and
Johanna Penteker.
Abstract: We constructively determine the Pietsch measure of the
$2$-summing multiplication operator
\[\mathcal{M}_u:\ell^{\infty} \rightarrow H^p, \quad (\varphi_I) \mapsto
\sum \varphi_Ix_Ih_I. \] Our construction of the Pietsch measure for the
multiplication operator $\mathcal{M}_u$ involves the Haar coefficients
of $u$ and its atomic decomposition.
Archive classification: math.FA
Mathematics Subject Classification: 42B30 46B25 46B09 46B42 46E40
47B10 60G42
Remarks: 24 pages
Submitted from: johanna.penteker(a)jku.at
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1310.4312
or
http://arXiv.org/abs/1310.4312
This is an announcement for the paper "Some problems in functional
analysis inspired by Hahn Banach type theorems" by M. A. Sofi.
Abstract: As a cornerstone of functional analysis, Hahn Banach theorem
constitutes an indispensable tool of modern analysis where its impact
extends beyond the frontiers of linear functional analysis into several
other domains of mathematics, including complex analysis, partial
differential equations and ergodic theory besides many more. The paper is
an attempt to draw attention to certain applications of the Hahn Banach
theorem which are less familiar to the mathematical community, apart from
highlighting certain aspects of the Hahn Banach phenomena which have
spurred intense research activity over the past few years, especially
involving operator analogues and nonlinear variants of this theorem.
Archive classification: math.FA
Mathematics Subject Classification: 46B20, 47B10, 46G10
Remarks: 29 pages, 0 figures, accepted in Ann. Func. Anal
Submitted from: aminsofi(a)kashmiruniversity.ac.in
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1310.3382
or
http://arXiv.org/abs/1310.3382
This is an announcement for the paper "A note on the Bishop property in
compact spaces" by Tomasz Kania and Richard J. Smith.
Abstract: We answer two questions concerning the Bishop property
($\symbishop$), introduced recently by K.P. Hart, T. Kochanek and
the first-named author. There are two versions of ($\symbishop$):
one applies to linear operators and the other to compact Hausdorff
spaces. We show that if $\mathscr{D}$ is a class of compact spaces that
is preserved when taking closed subspaces and Hausdorff quotients, and
which contains no non-metrizable linearly ordered space, then every member
of $\mathscr{D}$ has ($\symbishop$). Examples of such classes include
all $K$ for which $C(K)$ is Lindel\"of in the topology of pointwise
convergence (for instance, all Corson compact spaces) and the class of
Gruenhage compact spaces. We also show that the set of operators on a
$C(K)$-space satisfying ($\symbishop$) does not form a right ideal in
$\mathscr{B}(C(K))$. Some results regarding local connectedness are
also presented.
Archive classification: math.GN math.FA
Submitted from: t.kania(a)lancaster.ac.uk
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1310.4035
or
http://arXiv.org/abs/1310.4035
This is an announcement for the paper "A universal operator on the
Gurarii space" by Joanna Garbulinska-Wegrzyn and Wieslaw Kubis.
Abstract: We construct a nonexpansive linear operator on the Gurarii space
that ``captures" all nonexpansive linear operators between separable
Banach spaces. Some additional properties involving its restrictions
to finite-dimensional subspaces describe this operator uniquely up to
an isometry.
Archive classification: math.FA
Mathematics Subject Classification: 47A05, 47A65, 46B04
Remarks: 17 pages
Submitted from: kubis(a)math.cas.cz
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1310.2380
or
http://arXiv.org/abs/1310.2380
This is an announcement for the paper "No greedy bases for matrix spaces
with mixed $\ell_p$ and $\ell_q$" by Gideon Schechtman.
Abstract: We show that non of the spaces
$(\bigoplus_{n=1}^\infty\ell_p)_{\ell_q}$, $1\le p\not= q<\infty$, have a
greedy basis. This solves a problem raised by Dilworth, Freeman, Odell and
Schlumprect. Similarly, the spaces $(\bigoplus_{n=1}^\infty\ell_p)_{c_0}$,
$1\le p<\infty$, and $(\bigoplus_{n=1}^\infty c_o)_{\ell_q}$, $1\le
q<\infty$, do not have greedy bases. It follows from that and known
results that a class of Besov spaces on $\R^n$ lack greedy bases as well.
Archive classification: math.FA
Mathematics Subject Classification: 46B15, 41A65, 46B45, 46E35
Submitted from: gideon(a)weizmann.ac.il
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1310.2371
or
http://arXiv.org/abs/1310.2371
This is an announcement for the paper "Compact lines and the Sobczyk
property" by Claudia Correa and Daniel V. Tausk.
Abstract: We show that Sobczyk's Theorem holds for a new class of
Banach spaces, namely spaces of continuous functions on linearly ordered
compacta.
Archive classification: math.FA
Mathematics Subject Classification: 46B20, 46E15, 54F05
Remarks: 12 pages
Submitted from: tausk(a)ime.usp.br
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1310.1950
or
http://arXiv.org/abs/1310.1950
This is an announcement for the paper "A version of Kalton's theorem
for the space of regular operators" by Foivos Xanthos.
Abstract: In this note we extend some recent results in the space of
regular operators. In particular, we provide the following Banach lattice
version of a classical result of Kalton: Let $E$ be an atomic Banach
lattice with an order continuous norm and $F$ a Banach lattice. Then
the following are equivalent: (i) $L^r(E,F)$ contains no copy of
$\ell_\infty$, \,\, (ii) $L^r(E,F)$ contains no copy of $c_0$, \,\,
(iii) $K^r(E,F)$ contains no copy of $c_0$, \,\, (iv) $K^r(E,F)$ is a
(projection) band in $L^r(E,F)$, \,\, (v) $K^r(E,F)=L^r(E,F)$.
Archive classification: math.FA
Submitted from: foivos(a)ualberta.ca
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1310.1591
or
http://arXiv.org/abs/1310.1591