This is an announcement for the paper "Explicit matrices with the
Restricted Isometry Property: Breaking the square-root bottleneck"
by Dustin G. Mixon.
Abstract: Matrices with the restricted isometry property (RIP) are
of particular interest in compressed sensing. To date, the best
known RIP matrices are constructed using random processes, while
explicit constructions are notorious for performing at the "square-root
bottleneck," i.e., they only accept sparsity levels on the order of the
square root of the number of measurements. The only known explicit matrix
which surpasses this bottleneck was constructed by Bourgain, Dilworth,
Ford, Konyagin and Kutzarova. This chapter provides three contributions
to further the groundbreaking work of Bourgain et al.: (i) we develop an
intuition for their matrix construction and underlying proof techniques;
(ii) we prove a generalized version of their main result; and (iii)
we apply this more general result to maximize the extent to which their
matrix construction surpasses the square-root bottleneck.
Archive classification: math.FA cs.IT math.CO math.IT
Remarks: Book chapter, submitted to Compressed Sensing and its
Applications
Submitted from: dustin.mixon(a)gmail.com
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1403.3427
or
http://arXiv.org/abs/1403.3427
This is an announcement for the paper "Weak compactness of almost limited
operators" by A. Elbour, N. Machrafi, and M. Moussa.
Abstract: The paper is devoted to the relationship between almost limited
operators and weakly compacts operators. We show that if $F$ is a $\sigma
$-Dedekind complete Banach lattice then, every almost limited operator
$T:E\rightarrow F $ is weakly compact if and only if $E$ is reflexive
or the norm of $F$ is order continuous. Also, we show that if $E$ is
a $\sigma $-Dedekind complete Banach lattice then the square of every
positive almost limited operator $ T:E\rightarrow E$ is weakly compact
if and only if the norm of $E$ is order continuous.
Archive classification: math.FA
Mathematics Subject Classification: 46B42 (Primary) 46B50, 47B65
(Secondary)
Remarks: 5 pages
Submitted from: azizelbour(a)hotmail.com
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1403.3348
or
http://arXiv.org/abs/1403.3348
This is an announcement for the paper "WORTH property, Garc\'{i}a-Falset
coefficient and Opial property of infinite sums" by Jan-David Hardtke.
Abstract: We prove some results concerning the WORTH property and
the Garc\'{i}a-Falset coefficient of absolute sums of infinitely many
Banach spaces. The Opial property/uniform Opial property of infinite
$\ell^p$-sums is also studied and some properties analogous to the Opial
property/uniform Opial property for Lebesgue-Bochner spaces $L^p(\mu,X)$
are discussed.
Archive classification: math.FA
Mathematics Subject Classification: 46B20 46E40
Remarks: 22 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/1403.2647
or
http://arXiv.org/abs/1403.2647
This is an announcement for the paper "Coarse quotient mappings between
metric spaces" by Sheng Zhang.
Abstract: We give a definition of coarse quotient mapping and show
that several results for uniform quotient mapping also hold in the
coarse setting. In particular, we prove that any Banach space that is
a coarse quotient of $L_p\equiv L_p[0,1]$, $1<p<\infty$, is isomorphic
to a linear quotient of $L_p$. It is also proved that $\ell_q$ is not a
coarse quotient of $\ell_p$ for $1<p<q<\infty$ using Rolewicz's property
($\beta$).
Archive classification: math.FA math.MG
Submitted from: z1986s(a)math.tamu.edu
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1403.1934
or
http://arXiv.org/abs/1403.1934
This is an announcement for the paper "Lineability of non-differentiable
Pettis primitives" by B. Bongiorno, U. B. Darju, and L. Di Piazza.
Abstract: Let X be an in?nite-dimensional Banach space. In 1995, settling
a long outstanding problem of Pettis, Dilworth and Girardi constructed an
X-valued Pettis integrable function on [0; 1] whose primitive is nowhere
weakly di?erentiable. Using their technique and some new ideas we show
that ND, the set of strongly measurable Pettis integrable functions with
nowhere weakly di?erentiable primitives, is lineable, i.e., there is an
in?nite dimensional vector space whose nonzero vectors belong to ND.
Archive classification: math.FA
Mathematics Subject Classification: 46G10, 28B05
Submitted from: ubdarj01(a)louisville.edu
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1403.1908
or
http://arXiv.org/abs/1403.1908
This is an announcement for the paper "New Orlicz affine isoperimetric
inequalities" by Deping Ye.
Abstract: The Orlicz-Brunn-Minkowski theory receives considerable
attention recently, and many results in the $L_p$-Brunn-Minkowski theory
have been extended to their Orlicz counterparts. The aim of this paper
is to develop Orlicz $L_{\phi}$ affine and geominimal surface areas
for single convex body as well as for multiple convex bodies, which
generalize the $L_p$ (mixed) affine and geominimal surface areas --
fundamental concepts in the $L_p$-Brunn-Minkowski theory. Our extensions
are different from the general affine surface areas by Ludwig (in
Adv. Math. 224 (2010)). Moreover, our definitions for Orlicz $L_{\phi}$
affine and geominimal surface areas reveal that these affine invariants
are essentially the infimum/supremum of $V_{\phi}(K, L^\circ)$, the Orlicz
$\phi$-mixed volume of $K$ and the polar body of $L$, where $L$ runs over
all star bodies and all convex bodies, respectively, with volume of $L$
equal to the volume of the unit Euclidean ball $B_2^n$. Properties for
the Orlicz $L_{\phi}$ affine and geominimal surface areas, such as,
affine invariance and monotonicity, are proved. Related Orlicz affine
isoperimetric inequalities are also established.
Archive classification: math.MG math.DG math.FA
Mathematics Subject Classification: 52A20, 53A15
Submitted from: deping.ye(a)gmail.com
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1403.1643
or
http://arXiv.org/abs/1403.1643
This is an announcement for the paper "Dual spaces to Orlicz - Lorentz
spaces" by Anna Kaminska, Karol Lesnik, and Yves Raynaud.
Abstract: For an Orlicz function $\varphi$ and a decreasing weight $w$,
two intrinsic exact descriptions are presented for the norm in the
K\"othe dual of an Orlicz-Lorentz function space $\Lambda_{\varphi,w}$
or a sequence space $\lambda_{\varphi,w}$, equipped with either
Luxemburg or Amemiya norms. The first description of the dual norm is
given via the modular $\inf\{\int\varphi_*(f^*/|g|)|g|: g\prec w\}$,
where $f^*$ is the decreasing rearrangement of $f$, $g\prec w$ denotes
the submajorization of $g$ by $w$ and $\varphi_*$ is the complementary
function to $\varphi$. The second one is stated in terms of the modular
$\int_I \varphi_*((f^*)^0/w)w$, where $(f^*)^0$ is Halperin's level
function of $f^*$ with respect to $w$. That these two descriptions
are equivalent results from the identity $\inf\{\int\psi(f^*/|g|)|g|:
g\prec w\}=\int_I \psi((f^*)^0/w)w$ valid for any measurable function $f$
and Orlicz function $\psi$. Analogous identity and dual representations
are also presented for sequence spaces.
Archive classification: math.FA
Mathematics Subject Classification: 42B25, 46B10, 46E30
Remarks: 25 pages
Submitted from: klesnik(a)vp.pl
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1403.1505
or
http://arXiv.org/abs/1403.1505
This is an announcement for the paper "A proof of Rosenthal's \(\ell_1\)
Theorem" by Ioannis Gasparis.
Abstract: A proof is given of Rosenthal's \(\ell_1\) theorem.
Archive classification: math.FA
Mathematics Subject Classification: 46B03
Remarks: 5 pages
Submitted from: ioagaspa(a)math.ntua.gr
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1403.1163
or
http://arXiv.org/abs/1403.1163
This is an announcement for the paper "On the $c_0$-extension property
for compact lines" by Claudia Correa and Daniel V. Tausk.
Abstract: We present a characterization of the continuous increasing
surjections $\phi:K\to L$ between compact lines $K$ and $L$ for which
the corresponding subalgebra $\phi^*C(L)$ has the $c_0$-extension
property in $C(K)$. A natural question arising in connection with this
characterization is shown to be independent of the axioms of ZFC.
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/1403.0605
or
http://arXiv.org/abs/1403.0605
This is an announcement for the paper "On the class of weak almost
limited operators" by A. Elbour, N. Machrafi, and M. Moussa.
Abstract: We introduce and study the class of weak almost limited
operators. We establish a characterization of pairs of Banach lattices
$E$, $F$ for which every positive weak almost limited operator
$T:E\rightarrow F$ is almost limited (resp. almost Dunford-Pettis). As
consequences, we will give some interesting results.
Archive classification: math.FA
Mathematics Subject Classification: 46B42 (Primary) 46B50, 47B65
(Secondary)
Submitted from: azizelbour(a)hotmail.com
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1403.0136
or
http://arXiv.org/abs/1403.0136