This is an announcement for the paper "Chaining, Interpolation, and
Convexity" by Ramon van Handel.
Abstract:
We show that classical chaining bounds on the suprema of random
processes in terms of entropy numbers can be systematically improved
when the underlying set is convex: the entropy numbers need not be
computed for the entire set, but only for certain "thin" subsets. This
phenomenon arises from the observation that real interpolation can be used
as a natural chaining mechanism. Unlike the general form of Talagrand's
generic chaining method, which is sharp but often difficult to use, the
resulting bounds involve only entropy numbers but are nonetheless sharp
in many situations in which classical entropy bounds are suboptimal. Such
bounds are readily amenable to explicit computations in specific examples,
and we discover some old and new geometric principles for the control
of chaining functionals as special cases.
Archive classification: math.PR math.FA math.MG
Mathematics Subject Classification: 60B11, 60G15, 41A46, 46B20, 46B70
Remarks: 20 pages
Submitted from: rvan(a)princeton.edu
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1508.05906
or
http://arXiv.org/abs/1508.05906
This is an announcement for the paper "$L^p$-norms and Mahler's measure
of polynomials on the $n$-dimensional torus" by Andreas Defant and
Mieczyslaw Mastylo.
Abstract:
We prove Nikol'skii type inequalities which for polynomials on the
$n$-dimensional torus $\mathbb{T}^n$ relate the $L^p$-with the $L^q$-norm
(with respect to the normalized Lebesgue measure and $0 <p <q <
\infty$). Among other things we show that $C=\sqrt{q/p}$ is the best
constant such that $\|P\|_{L^q}\leq C^{\text{deg}(P)} \|P\|_{L^p}$ for
all homogeneous polynomials $P$ on $\mathbb{T}^n$. We also prove an exact
inequality between the $L^p$-norm of a polynomial $P$ on $\mathbb{T}^n$
and its Mahler measure $M(P)$, which is the geometric mean of $|P|$
with respect to the normalized Lebesgue measure on $\mathbb{T}^n$. Using
extrapolation we transfer this estimate into a Khintchine-Kahane type
inequality, which, for polynomials on $\mathbb{T}^n$, relates a certain
exponential Orlicz norm and Mahler's measure. Applications are given,
including some interpolation estimates.
Archive classification: math.FA
Mathematics Subject Classification: 11R06, 11C08
Submitted from: mastylo(a)amu.edu.pl
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1508.05556
or
http://arXiv.org/abs/1508.05556
This is an announcement for the paper "Bohnenblust-Hille inequalities
for Lorentz spaces via interpolation" by Andreas Defant and Mieczyslaw
Mastylo.
Abstract:
We prove that the Lorentz sequence space $\ell_{\frac{2m}{m+1},1}$
is, in a~precise sense, optimal among all symmetric Banach sequence
spaces satisfying a Bohnenblust-Hille type inequality for $m$-linear
forms or $m$-homogeneous polynomials on $\mathbb{C}^n$. Motivated by this
result we develop methods for dealing with subtle Bohnenblust-Hille type
inequalities in the setting of Lorentz spaces. Based on an interpolation
approach and the Blei-Fournier inequalities involving mixed type spaces,
we prove multilinear and polynomial Bohnenblust-Hille type inequalities in
Lorentz spaces with subpolynomial and subexponential constants. Improving
a remarkable result of Balasubramanian-Calado-Queff\'{e}lec, we show an
application to the theory of Dirichlet series.
Archive classification: math.FA
Mathematics Subject Classification: 46B70, 47A53
Submitted from: mastylo(a)amu.edu.pl
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1508.05554
or
http://arXiv.org/abs/1508.05554
This is an announcement for the paper "On conditional weak topologies
under a simplified approach derived the framework of conditional sets"
by Jose Miguel Zapata.
Abstract:
The purpose of this manuscript is to introduce a simplified approach
derived from the framework of conditional sets, which is a novel
approach to study dynamic and conditional settings, as those that
arise in mathematical finance. Under this approach, and with the aim
of providing an analytic basis for the study of dynamic and conditional
risk measures, we carry out a study of the conditional weak topologies
and conditional weak compactness, extending some well-known results to
this framework and culminating with the proof of conditional versions of
Eberlein-\v{S}mulian and Amir-Lindenstrauss Theorems. In pursuing this
aim we study the algebraic structure of conditional spaces conditionally
finitely generated and state conditional versions of Baire Category
Theorem and Uniform Boundedness Principle.
Archive classification: math.FA
Submitted from: jmzg1(a)um.es
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1508.05112
or
http://arXiv.org/abs/1508.05112
This is an announcement for the paper "Non-universal families of separable
Banach spaces" by Ondrej Kurka.
Abstract:
We prove that if $ C $ is a family of separable Banach spaces which is
analytic with respect to the Effros-Borel structure and none member
of $ C $ is isometrically universal for all separable Banach spaces,
then there exists a separable Banach space with a monotone Schauder
basis which is isometrically universal for $ C $ but still not for all
separable Banach spaces. We also establish an analogous result for the
class of strictly convex spaces.
Archive classification: math.FA
Mathematics Subject Classification: 46B04, 54H05 (Primary) 46B15, 46B20,
46B25 (Secondary)
Submitted from: kurka.ondrej(a)seznam.cz
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1508.05059
or
http://arXiv.org/abs/1508.05059
This is an announcement for the paper "Almost disjointness preservers"
by Timur Oikhberg and Pedro Tradacete.
Abstract:
We study the stability of disjointness preservers on Banach lattices. In
many cases, we prove that an ``almost disjointness preserving'' operator
is well approximable by a disjointess preserving one. However, this
approximation is not always possible, as our examples show.
Archive classification: math.FA
Mathematics Subject Classification: 47B38, 46B42
Remarks: 43 pages
Submitted from: ptradace(a)math.uc3m.es
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1508.04074
or
http://arXiv.org/abs/1508.04074
This is an announcement for the paper "Narrow operators on lattice-normed
spaces and vector measures" by D.T. Dzadzaeva and M.A. Pliev.
Abstract:
We consider linear narrow operators on lattice-normed spaces. We prove
that, under mild assumptions, every finite rank linear operator
is strictly narrow (before it was known that such operators are
narrow). Then we show that every dominated, order continuous linear
operator from a lattice-normed space over atomless vector lattice to an
atomic lattice-normed space is order narrow.
Archive classification: math.FA
Mathematics Subject Classification: Primary 46B99, Secondary 46G12
Submitted from: martin.weber(a)tu-dresden.de
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1508.03995
or
http://arXiv.org/abs/1508.03995
This is an announcement for the paper "An uniform estimate of the relative
projection constant" by Tomasz Kobos.
Abstract:
The main goal of the paper is to provide a quantitative lower bound
greater than $1$ for the relative projection constant $\lambda(Y, X)$,
where $X$ is a subspace of $\ell_{2p}^m$ space and $Y \subset X$ is an
arbitrary hyperplane. As a consequence, we establish that for every
integer $n \geq 4$ there exists an $n$-dimensional normed space $X$
such that for an every hyperplane $Y$ and every projection $P:X \to
Y$ the inequality $||P|| > 1 + \left (2 \left ( n + 3 \right )^{2}
\right )^{-100(n+3)^2}$ holds. This gives a non-trivial lower bound in
a variation of problem proposed by Bosznay and Garay in $1986$.
Archive classification: math.FA
Mathematics Subject Classification: 47A58, 41A65, 47A30, 52A21
Remarks: 15 pages
Submitted from: tkobos(a)wp.pl
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1508.03518
or
http://arXiv.org/abs/1508.03518
This is an announcement for the paper "Dominated oprerators from
a lattice-normed space to a sequence Banach lattice" by Abasov,N.,
Megaled,A., and Pliev,M.
Abstract:
Abstract. We show that every dominated linear operator from an
Banach-Kantorovich space over atomless Dedekind complete vector lattice to
a sequence Banach lattice $l_p({\Gamma})$ or $c_0({\Gamma})$ is narrow. As
a conse- quence, we obtain that an atomless Banach lattice cannot have a
finite dimensional decomposition of a certain kind. Finally we show that
if a linear dominated operator T from lattice-normed space V to Banach-
Kantorovich space W is order narrow then the same is its exact dominant
$\ls T\rs$.
Archive classification: math.FA
Mathematics Subject Classification: 47H30, 46B42
Submitted from: martin.weber(a)tu-dresden.de
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1508.03275
or
http://arXiv.org/abs/1508.03275
This is an announcement for the paper "Duality on Banach spaces and a
Borel parametrized version of Zippin's theorem" by Bruno de Mendonca
Braga.
Abstract:
Let SB be the standard coding for separable Banach spaces as subspaces
of $C(\Delta)$. In these notes, we show that if $\mathbb{B} \subset
\text{SB}$ is a Borel subset of spaces with separable dual, then
the assignment $X \mapsto X^*$ can be realized by a Borel function
$\mathbb{B}\to \text{SB}$. Moreover, this assignment can be done in
such a way that the functional evaluation is still well defined (Theorem
$1$). Also, we prove a Borel parametrized version of Zippin's theorem,
i.e., we prove that there exists $Z \in \text{SB}$ and a Borel function
that assigns for each $X \in \mathbb{B}$ an isomorphic copy of $X$
inside of $Z$ (Theorem $5$).
Archive classification: math.FA
Submitted from: demendoncabraga(a)gmail.com
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1508.02066
or
http://arXiv.org/abs/1508.02066