This is an announcement for the paper "Concentration phenomena in high
dimensional geometry" by Olivier Guedon.
Abstract: The purpose of this note is to present several aspects of
concentration phenomena in high dimensional geometry. At the heart of
the study is a geometric analysis point of view coming from the theory
of high dimensional convex bodies. The topic has a broad audience going
from algorithmic convex geometry to random matrices. We have tried to
emphasize different problems relating these areas of research. Another
connected area is the study of probability in Banach spaces where some
concentration phenomena are related with good comparisons between the
weak and the strong moments of a random vector.
Archive classification: math.FA
Remarks: This paper is written after a plenary talk given in August
2012 at the "Journ\'ees MAS" organized in Clermont Ferrand. To appear
in ESAIM Proceedings
Submitted from: olivier.guedon(a)univ-mlv.fr
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1310.1204
or
http://arXiv.org/abs/1310.1204
This is an announcement for the paper "Dual affine invariant points"
by Mathieu Meyer, Carsten Schuett, and Elisabeth M. Werner.
Abstract: An affine invariant point on the class of convex bodies in
R^n, endowed with the Hausdorff metric, is a continuous map p which is
invariant under one-to-one affine transformations A on R^n, that is,
p(A(K))=A(p(K)).
We define here the new notion of dual affine point q of an affine
invariant point p by the formula q(K^{p(K)})=p(K) for every convex body K,
where K^{p(K)} denotes the polar of K with respect to p(K).
We investigate which affine invariant points do have a dual point,
whether this dual point is unique and has itself a dual point. We define
a product on the set of affine invariant points, in relation with duality.
Finally, examples are given which exhibit the rich structure of the
set of affine invariant points.
Archive classification: math.FA
Submitted from: elisabeth.werner(a)case.edu
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1310.0128
or
http://arXiv.org/abs/1310.0128
This is an announcement for the paper "Quasi-Banach spaces of almost
universal disposition" by Felix Cabello Sanchez, Joanna Garbulinska,
and Wieslaw Kubis.
Abstract: We show that for each $p\in(0,1]$ there exists a separable
$p$-Banach space $\mathbb G_p$ of almost universal disposition, that
is, having the following extension property: for each $\epsilon>0$ and
each isometric embedding $g:X\to Y$, where $Y$ is a finite dimensional
$p$-Banach space and $X$ is a subspace of $\mathbb G_p$, there is an
$\epsilon$-isometry $f:Y\to \mathbb G_p$ such that $x=f(g(x))$ for all
$x\in X$.
Such a space is unique, up to isometries, does contain an isometric copy
of each separable $p$-Banach space and has the remarkable property of
being ``locally injective'' amongst $p$-Banach spaces.
We also present a nonseparable generalization which is of universal
disposition for separable spaces and ``separably injective''. No separably
injective $p$-Banach space was previously known for $p<1$.
Archive classification: math.FA
Mathematics Subject Classification: 46A16, 46B04
Remarks: 22 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/1309.7649
or
http://arXiv.org/abs/1309.7649
This is an announcement for the paper "Operators on Banach spaces of
Bourgain-Delbaen type" by Matthew Tarbard.
Abstract: We begin by giving a detailed exposition of the original
Bourgain-Delbaen construction and the generalised construction due to
Argyros and Haydon. We show how these two constructions are related,
and as a corollary, are able to prove that there exists some $\delta >
0$ and an uncountable set of isometries on the original Bourgain-Delbaen
spaces which are pairwise distance $\delta$ apart.
We subsequently extend these ideas to obtain our main results. We
construct new Banach spaces of Bourgain-Delbaen type, all of which
have $\ell_1$ dual. The first class of spaces are HI and possess few,
but not very few operators. We thus have a negative solution to the
Argyros-Haydon question. We remark that all these spaces have finite
dimensional Calkin algebra, and we investigate the corollaries of this
result. We also construct a space with $\ell_1$ Calkin algebra and show
that whilst this space is still of Bourgain-Delbaen type with $\ell_1$
dual, it behaves somewhat differently to the first class of spaces.
Finally, we briefly consider shift-invariant $\ell_1$ preduals,
and hint at how one might use the Bourgain-Delbaen construction to
produce new, exotic examples.
Archive classification: math.FA
Remarks: Oxford University DPhil Thesis
Submitted from: matthew.tarbard(a)sjc.ox.ac.uk
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/1309.7469
or
http://arXiv.org/abs/1309.7469
1st ANNOUNCEMENT OF BWB 2014
First Brazilian Workshop in Geometry of Banach Spaces
August 25-29, 2014
Maresias, São Paulo State, Brazil.
This is the 1st announcement for the First Brazilian Workshop in
Geometry of Banach Spaces, organized by the University of São Paulo
(USP), in the week August 25-29, 2014.
This international conference will take place at the Beach Hotel
Maresias, on the coast of São Paulo State, in Maresias. The scientific
program will focus on the theory of geometry of Banach spaces, with
emphasis on the following directions: linear theory of infinite
dimensional spaces and its relations to Ramsey theory, homological
theory and set theory; nonlinear theory; and operator theory.
The webpage of the Workshop may be found at
http://www.ime.usp.br/~banach/bwb2014/
Registration will start in early 2014. Additional scientific,
practical and financial information will be given at that time.
Plenary speakers:
S. A. Argyros (Nat. Tech. U. Athens)
J. M. F. Castillo (U. Extremadura)
P. Dodos (U. Athens)
G. Godefroy (Paris 6)
R. Haydon (U. Oxford)
W. B. Johnson (Texas A&M)
P. Koszmider (Polish Acad. Warsaw)
G. Pisier (Paris 6 & Texas A&M)
C. Rosendal (U. Illinois Chicago)
G. Schechtman (Weizmann Inst.)
Th. Schlumprecht (Texas A&M)
S. Todorcevic (Paris 7 & U. Toronto)
Scientific committee
J. M. F. Castillo (U. Extremadura)
V. Ferenczi (U. São Paulo)
R. Haydon (U. Oxford)
W. B. Johnson (Texas A&M)
G. Pisier (Paris 6 & Texas A&M)
Th. Schlumprecht (Texas A&M)
S. Todorcevic (Paris 7 & U. Toronto)
We are looking forward to meeting you next year in Brazil,
F. Baudier, C. Brech, V. Ferenczi, E. M. Galego, and J. Lopez-Abad.