This is an announcement for the paper "On classes of Banach spaces
admitting ``small" universal spaces" by Pandelis Dodos.
Abstract: We characterize those classes $\ccc$ of separable Banach
spaces admitting a separable universal space $Y$ (that is, a space $Y$
containing, up to isomorphism, all members of $\ccc$) which is not
universal for all separable Banach spaces. The characterization is a
byproduct of the fact, proved in the paper, that the class $\mathrm{NU}$
of non-universal separable Banach spaces is strongly bounded. This settles
in the affirmative the main conjecture form \cite{AD}. Our approach
is based, among others, on a construction of $\llll_\infty$-spaces,
due to J. Bourgain and G. Pisier. As a consequence we show that there
exists a family $\{Y_\xi:\xi<\omega_1\}$ of separable, non-universal,
$\llll_\infty$-spaces which uniformly exhausts all separable Banach
spaces. A number of other natural classes of separable Banach spaces
are shown to be strongly bounded as well.
Archive classification: math.FA math.LO
Mathematics Subject Classification: 03E15, 46B03, 46B07, 46B15
Remarks: 25 pages, no figures
The source file(s), Universal-ArXiv.tex: 81806 bytes, is(are) stored in
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Submitted from: pdodos(a)math.ntua.gr
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This is an announcement for the paper "On antichains of spreading models
of Banach spaces" by Pandelis Dodos.
Abstract: We show that for every separable Banach space $X$, either
$\spw(X)$ (the set of all spreading models of $X$ generated by weakly-null
sequences in $X$, modulo equivalence) is countable, or $\spw(X)$ contains
an antichain of the size of the continuum. This answers a question of
S. J. Dilworth, E. Odell and B. Sari.
Archive classification: math.FA math.LO
Mathematics Subject Classification: 03E15, 46B20
Remarks: 14 pages, no figures. Canadian Mathematical Bulletin (to appear)
The source file(s), SP-ArXiv.tex: 44752 bytes, is(are) stored in gzipped
form as 0805.2038.gz with size 13kb. The corresponding postcript file
has gzipped size 96kb.
Submitted from: pdodos(a)math.ntua.gr
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http://front.math.ucdavis.edu/0805.2038
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This is an announcement for the paper "Definability under duality"
by Pandelis Dodos.
Abstract: It is shown that if $A$ is an analytic class of separable Banach
spaces with separable dual, then the set $A^*=\{ Y:\exists X\in A \text{
with } Y\cong X^*\}$ is analytic. The corresponding result for pre-duals
is false.
Archive classification: math.FA math.LO
Mathematics Subject Classification: 03E15, 46B10
Remarks: 9 pages, no figures
The source file(s), DualsVersion-ArXiv.tex: 29048 bytes, is(are) stored
in gzipped form as 0805.2036.gz with size 9kb. The corresponding postcript
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Submitted from: pdodos(a)math.ntua.gr
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/0805.2036
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http://arXiv.org/abs/0805.2036
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This is an announcement for the paper "Unconditional basic sequences
in spaces of large density" by Pandelis Dodos, Jordi Lopez Abad and
Stevo Todorcevic.
Abstract: We study the problem of the existence of unconditional basic
sequences in Banach spaces of high density. We show, in particular,
the relative consistency with GCH of the statement that every Banach
space of density $\aleph_\omega$ contains an unconditional basic sequence.
Archive classification: math.FA math.LO
Mathematics Subject Classification: 46B03, 03E35
The source file(s), DLT.tex: 74305 bytes, is(are) stored in gzipped
form as 0805.1860.gz with size 22kb. The corresponding postcript file
has gzipped size 136kb.
Submitted from: abad(a)logique.jussieu.fr
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/0805.1860
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http://arXiv.org/abs/0805.1860
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This is an announcement for the paper "Embeddings between operator-valued
dyadic BMO spaces" by Oscar Blasco and Sandra Pott.
Abstract: We investigate a scale of dyadic operator-valued BMO spaces,
corresponding to the different yet equivalent characterizations of dyadic
BMO in the scalar case. In the language of operator spaces, we investigate
different operator space structures on the scalar dyadic BMO space which
arise naturally from the different characterisations of scalar BMO. We
also give sharp dimensional growth estimates for the sweep of functions
and its bilinear extension in some of those different dyadic BMO spaces.
Archive classification: math.FA
Mathematics Subject Classification: Primary 42B30, 42B35, Secondary 47B35
Remarks: to appear in Illinois J. Math
The source file(s), BlascoPott2.tex: 45114 bytes, is(are) stored in
gzipped form as 0805.0620.gz with size 14kb. The corresponding postcript
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Submitted from: s.pott(a)maths.gla.ac.uk
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On May 27-28 the Institute of Mathematics of the
Hebrew University of Jerusalem is organizing a memorial
symposium for Lior Tzafriri, titled "Geometry of Banach Spaces".
A tentative program of the symposium can be found on the webpage:
http://www.ma.huji.ac.il/~landau/conf/banach_08.html
This is an announcement for the paper "A compact null set containing a
differentiability point of every Lipschitz function" by Michael Doree and
Olga Maleva.
Abstract: We prove that in a Euclidean space of dimension at least
two, there exists a compact set of Lebesgue measure zero such that any
real-valued Lipschitz function defined on the space is differentiable
at some point in the set. Such a set is constructed explicitly.
Archive classification: math.FA math.CA
Mathematics Subject Classification: 46G05; 46T20
Remarks: 31 pages
The source file(s), DoreMaleva.tex: 76535 bytes, is(are) stored in gzipped
form as 0804.4576.gz with size 22kb. The corresponding postcript file
has gzipped size 144kb.
Submitted from: o.maleva(a)warwick.ac.uk
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/0804.4576
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http://arXiv.org/abs/0804.4576
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This is an announcement for the paper "The isometry group of L^{p}(\mu,\X)
is SOT-contractible" by Jarno Talponen.
Abstract: We will show that if (\Omega,\Sigma,\mu) is an atomless
positive measure space, X is a Banach space and 1\leq p<\infty, then
the group of isometric automorphisms on the Bochner space L^{p}(\mu,X)
is contractible in the strong operator topology. We do not require \Sigma
or X above to be separable.
Archive classification: math.FA
Mathematics Subject Classification: 46B04; 46B25; 46E40
The source file(s), contr32.tex: 27449 bytes, is(are) stored in gzipped
form as 0804.4427.gz with size 9kb. The corresponding postcript file
has gzipped size 75kb.
Submitted from: talponen(a)cc.helsinki.fi
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http://front.math.ucdavis.edu/0804.4427
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This is an announcement for the paper "Functional inequalities derived
from the Brunn-Minkowski inequalities for quermassintegrals" by Andrea
Colesanti and Eugenia Saorin-Gomez.
Abstract: We use Brunn-Minkowski inequalities for quermassintegrals to
deduce a family of inequalities of Poincar\'e type on the unit sphere
and on the boundary of smooth convex bodies in the $n$-dimensional
Euclidean space.
Archive classification: math.FA math.MG
Mathematics Subject Classification: 52A20; 26D10
Remarks: 15 pages
The source file(s), cs3.tex: 37802 bytes, is(are) stored in gzipped
form as 0804.3867.gz with size 12kb. The corresponding postcript file
has gzipped size 109kb.
Submitted from: colesant(a)math.unifi.it
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http://front.math.ucdavis.edu/0804.3867
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This is an announcement for the paper "Conditions implying the uniqueness
of the weak$^*$-topology on certain group algebras" by Matthew Daws,
Hung Le Pham and Stuart White.
Abstract: We investigate possible preduals of the measure algebra $M(G)$
of a locally compact group and the Fourier algebra $A(G)$ of a separable
compact group. Both of these algebras are canonically dual spaces and the
canonical preduals make the multiplication separately weak$^*$-continuous
so that these algebras are dual Banach algebras. In this paper we find
additional conditions under which the preduals $C_0(G)$ of $M(G)$ and
$C^*(G)$ of $A(G)$ are uniquely determined. In both cases we consider a
natural coassociative multiplication and show that the canonical predual
gives rise to the unique weak$^*$-topology making both the multiplication
separately weak$^*$-continuous and the coassociative multiplication
weak$^*$-continuous. In particular, dual cohomological properties of
these algebras are well defined with this additional structure.
Archive classification: math.FA math.OA
Mathematics Subject Classification: 43A20, 43A77
Remarks: 21 pages
The source file(s), UniquePredualFinalDraft2.tex: 73814 bytes, is(are)
stored in gzipped form as 0804.3764.gz with size 22kb. The corresponding
postcript file has gzipped size 133kb.
Submitted from: matt.daws(a)cantab.net
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