This is an announcement for the paper "Estimating support functions of
random polytopes via Orlicz norms" by David Alonso-Gutierrez and Joscha
Prochno.
Abstract: We study the expected value of support functions of random
polytopes in a certain direction, where the random polytope is given
by independent random vectors uniformly distributed in an isotropic
convex body. All results are obtained by an utterly novel approach,
using probabilistic estimates in connection with Orlicz norms that were
not used in this connection before.
Archive classification: math.FA
Mathematics Subject Classification: Primary 52A22, Secondary 52A23,
05D40, 46B09
Submitted from: prochno(a)math.uni-kiel.de
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1205.2023
or
http://arXiv.org/abs/1205.2023
This is an announcement for the paper "Pointwise convergence of
vector-valued Fourier series" by Tuomas P. Hytonen and Michael T. Lacey.
Abstract: We prove a vector-valued version of Carleson's theorem:
Let Y=[X,H]_t be a complex interpolation space between a UMD space
X and a Hilbert space H. For p\in(1,\infty) and f\in L^p(T;Y), the
partial sums of the Fourier series of f converge to f pointwise almost
everywhere. Apparently, all known examples of UMD spaces are of this
intermediate form Y=[X,H]_t. In particular, we answer affirmatively a
question of Rubio de Francia on the pointwise convergence of Fourier
series of Schatten class valued functions.
Archive classification: math.FA math.CA
Mathematics Subject Classification: 42B20, 42B25
Remarks: 26 pages
Submitted from: tuomas.hytonen(a)helsinki.fi
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1205.0261
or
http://arXiv.org/abs/1205.0261
This is an announcement for the paper "Spaceability and algebrability of
sets of nowhere integrable functions" by Szymon Glab, Pedro L. Kaufmann
and Leonardo Pellegrini.
Abstract: We show that the set of Lebesgue integrable functions
in $[0,1]$ which are nowhere essentially bounded is spaceable,
improving a result from [F. J. Garc\'{i}a-Pacheco, M. Mart\'{i}n,
and J. B. Seoane-Sep\'ulveda. \textit{Lineability, spaceability,
and algebrability of certain subsets of function spaces,} Taiwanese
J. Math., \textbf{13} (2009), no. 4, 1257--1269], and that it is strongly
$\mathfrak{c}$-algebrable. We prove strong $\mathfrak{c}$-algebrability
and non-separable spaceability of the set of functions of bounded
variation which have a dense set of jump discontinuities. Applications to
sets of Lebesgue-nowhere-Riemann integrable and Riemann-nowhere-Newton
integrable functions are presented as corollaries. In addition
we prove that the set of Kurzweil integrable functions which are
not Lebesgue integrable is spaceable (in the Alexievicz norm)
but not $1$-algebrable. We also show that there exists an infinite
dimensional vector space $S$ of differentiable functions such that
each element of the $C([0,1])$-closure of $S$ is a primitive to a
Kurzweil integrable function, in connection to a classic spaceability
result from [V. I. Gurariy, \textit{Subspaces and bases in spaces of
continuous functions (Russian),} Dokl. Akad. Nauk SSSR, \textbf{167}
(1966), 971--973].
Archive classification: math.FA
Remarks: accepted on 2011
Submitted from: leoime(a)yahoo.com
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1204.6404
or
http://arXiv.org/abs/1204.6404
This is an announcement for the paper "The embedding of 2-concave
Musielak-Orlicz spaces into L_1 via l_2-matrix-averages" by Joscha
Prochno.
Abstract: In this note we prove that $\frac{1}{n!} \sum_{\pi} (
\sum_{i=1}^n |x_i a_{i,\pi(i)} |^2)^{\frac{1}{2}}$ is equivalent to a
Musielak-Orlicz norm $\norm{x}_{\sum M_i}$. We also obtain the inverse
result, i.e., given the Orlicz functions, we provide a formula for the
choice of the matrix that generates the corresponding Musielak-Orlicz
norm. As a consequence, we obtain the embedding of strictly 2-concave
Musielak-Orlicz spaces into L_1.
Archive classification: math.FA
Mathematics Subject Classification: 46B03, 05A20, 46B45
Submitted from: prochno(a)math.uni-kiel.de
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1204.6030
or
http://arXiv.org/abs/1204.6030
This is an announcement for the paper "Combinatorial inequalities and
subspaces of L1" by Joscha Prochno and Carsten Schuett.
Abstract: Let M and N be Orlicz functions. We establish some combinatorial
inequalities and show that the product spaces l^n_M(l^n_N) are uniformly
isomorphic to subspaces of L_1 if M and N are "separated" by a function
t^r, 1<r<2.
Archive classification: math.FA math.CO
Mathematics Subject Classification: 46B03, 05A20, 46B45, 46B09
Submitted from: prochno(a)math.uni-kiel.de
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1204.6025
or
http://arXiv.org/abs/1204.6025
This is an announcement for the paper "When is the Haar measure a Pietsch
measure for nonlinear mappings?" by G. Botelho, D. Pellegrino, P. Rueda,
J. Santos and J.B. Seoane-Sepulveda.
Abstract: We show that, as in the linear case, the normalized Haar measure
on a compact topological group $G$ is a Pietsch measure for nonlinear
summing mappings on closed translation invariant subspaces of $C(G)$. This
answers a question posed to the authors by J. Diestel. We also show that
our result applies to several well-studied classes of nonlinear summing
mappings. In the final section some problems are proposed.
Archive classification: math.FA
Submitted from: dmpellegrino(a)gmail.com
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1204.5621
or
http://arXiv.org/abs/1204.5621