This is an announcement for the paper "A solution to a question of
A. Koldobsky" by Emanuel Milman.
Abstract: In 2000, A. Koldobsky asked whether two types of
generalizations of the notion of an intersection-body, are in fact
equivalent. The structures of these two types of generalized
intersection-bodies have been studied by the author in
[http://www.arxiv.org/math.MG/0512058], providing substantial
positive evidence for a positive answer to this question. The purpose
of this note is to construct a counter-example, which provides a
surprising negative answer to this question in a strong sense. This
negative answer implies the existence of a non-trivial non-negative
function in the range of the spherical Radon transform.
Archive classification: Functional Analysis
Remarks: 13 pages
The source file(s), Solution-To-Koldobsky-Question.bbl: 5474 bytes,
Solution-To-Koldobsky-Question.tex: 41825 bytes, is(are) stored in
gzipped form as 0701779.tar.gz with size 14kb. The corresponding
postcript file has gzipped size 110kb.
Submitted from: emanuel.milman(a)weizmann.ac.il
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This is an announcement for the paper "Rosenthal operator spaces"
by Marius Junge, Niels Jorgen Nielsen and Timur Oikhberg.
Abstract: In 1969 Lindenstrauss and Rosenthal showed that if a
Banach space is isomorphic to a complemented subspace of an L_p-space,
then it is either a script L_p-space or isomorphic to a Hilbert
space. This is the motivation of this paper where we study
non--Hilbertian complemented operator subspaces of non commutative
L_p-spaces and show that this class is much richer than in the
commutative case. We investigate the local properties of some new
classes of operator spaces for every $2<p< \infty$ which can be
considered as operator space analogues of the Rosenthal sequence
spaces from Banach space theory, constructed in 1970. Under the
usual conditions on the defining sequence sigma we prove that most
of these spaces are operator script L_p-spaces, not completely
isomorphic to previously known such spaces. However it turns out
that some column and row versions of our spaces are not operator
script L_p-spaces and have a rather complicated local structure
which implies that the Lindenstrauss--Rosenthal alternative does
not carry over to the non-commutative case.
Archive classification: Functional Analysis
Mathematics Subject Classification: 46B20;46L07;46L52
The source file(s), njnpart1new11.tex: 38162 bytes, njnpart2new11.tex:
48325 bytes, refnew11.tex: 4840 bytes, rosmatrixnew11.tex: 10401
bytes, uncomp2.tex: 6528 bytes, x3njn1111.tex: 5668 bytes, is(are)
stored in gzipped form as 0701480.tar.gz with size 33kb. The
corresponding postcript file has gzipped size 176kb.
Submitted from: njn(a)imada.sdu.dk
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http://front.math.ucdavis.edu/math.FA/0701480
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This is an announcement for the paper "Projections and the
Kadison-Singer Problem" by Peter G. Casazza, Dan Edidin, Deepti
Kalra and Vern I. Paulsen.
Abstract: We prove some new equivalences of the paving conjecture
and obtain some estimates on the paving constants. In addition we
give a new family of counterexamples to one of the Akemann-Anderson
conjectures.
Archive classification: Functional Analysis
Mathematics Subject Classification: 46L15; 47L25
The source file(s), 127.Projks.tex: 48714 bytes, is(are) stored in
gzipped form as 0701450.gz with size 16kb. The corresponding postcript
file has gzipped size 123kb.
Submitted from: pete(a)math.missouri.edu
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http://front.math.ucdavis.edu/math.FA/0701450
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http://arXiv.org/abs/math.FA/0701450
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This is an announcement for the paper "On the ``Multiple of the
Inclusion Plus Compact'' problem" by George Androulakis and Frank
Sanacory.
Abstract: The ``multiple of the inclusion plus compact problem''
which was posed by T.W.~Gowers in 1996 and Th.~Schlumprecht in 2003,
asks whether for every infinite dimensional Banach space $X$ there
exists a closed subspace $Y$ of $X$ and a bounded linear operator
from $Y$ to $X$ which is not a compact perturbation of a multiple
of the inclusion map from $Y$ to $X$. We give sufficient conditions
on the spreading models of seminormalized basic sequences of a
Banach space $X$ which guarantee that the ``multiple of the inclusion
plus compact'' problem has an affirmative answer for $X$. Our results
strengthen a previous result of the first named author, E.~Odell,
Th.~Schlumprecht and N.~Tomczak-Jaegermann as well as a result of
Th.~Schlumprecht. We give an example of a Hereditarily Indecomposable
Banach space where our results apply. For the proof of our main
result we use an extension of E.~Odell's Schreier unconditionality
result for arrays.
Archive classification: Functional Analysis
Mathematics Subject Classification: 46A32, 47B07
The source file(s), lambdaipluscpt.tex: 114786 bytes, is(are) stored
in gzipped form as 0701354.gz with size 28kb. The corresponding
postcript file has gzipped size 203kb.
Submitted from: giorgis(a)math.sc.edu
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http://arXiv.org/abs/math.FA/0701354
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This is an announcement for the paper "Embedding into Banach spaces
with finite dimensional decompositions" by E. Odell and Th.
Schlumprecht.
Abstract: This paper deals with the following types of problems:
Assume a Banach space $X$ has some property (P). Can it be embedded
into some Banach space $Z$ with a finite dimensional decomposition
having property (P), or more generally, having a property related
to (P)? Secondly, given a class of Banach spaces, does there exist
a Banach space in this class, or in a closely related one, which
is universal for this class?
Archive classification: Functional Analysis
Mathematics Subject Classification: 46B03; 46B20
Remarks: 26 pages
The source file(s), os-embedding-final.tex: 109527 bytes, is(are)
stored in gzipped form as 0701324.gz with size 33kb. The corresponding
postcript file has gzipped size 182kb.
Submitted from: combs(a)mail.ma.utexas.edu
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http://front.math.ucdavis.edu/math.FA/0701324
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http://arXiv.org/abs/math.FA/0701324
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This is an announcement for the paper "The lower dimensional
Busemann-Petty problem for bodies with the generalized axial
symmetry" by Boris Rubin.
Abstract: The lower dimensional Busemann-Petty problem asks, whether
$n$-dimensional origin-symmetric convex bodies, having smaller
$i$-dimensional sections, necessarily have smaller volumes.
For $i=1$, the affirmative answer is obvious. For $i>3$, the answer
is negative.
For $i=2$ and $i=3$, the problem is still open, except when the body
with smaller sections is a body of revolution. In this case the answer is
affirmative. The paper contains a complete solution to the problem
in the more general situation, when the body with smaller sections
is invariant under orthogonal transformations preserving coordinate
subspaces $R^{l}$ and $R^{n-l}$ of $R^{n}$ for arbitrary fixed
$0<l<n$.
Archive classification: Functional Analysis
Mathematics Subject Classification: 44A12; 52A38
Remarks: 26 pages
The source file(s), simplex2.tex: 72011 bytes, is(are) stored in
gzipped form as 0701317.gz with size 23kb. The corresponding postcript
file has gzipped size 155kb.
Submitted from: borisr(a)math.lsu.edu
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http://front.math.ucdavis.edu/math.FA/0701317
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This is an announcement for the paper "Almost Euclidean sections
of the N-dimensional cross-polytope using O(N) random bits" by
Shachar Lovett and Sasha Sodin.
Abstract: It is well known that R^N has subspaces of dimension
proportional to N on which the \ell_1 norm is equivalent to the
\ell_2 norm; however, no explicit constructions are known. Extending
earlier work by Artstein--Avidan and Milman, we prove that such a
subspace can be generated using O(N) random bits.
Archive classification: Functional Analysis; Metric Geometry;
Probability
Remarks: 16 pages
The source file(s), derand.tex: 32081 bytes, is(are) stored in
gzipped form as 0701102.gz with size 11kb. The corresponding postcript
file has gzipped size 109kb.
Submitted from: sodinale(a)post.tau.ac.il
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http://front.math.ucdavis.edu/math.FA/0701102
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This is an announcement for the paper "the paving conjecture is
equivalent to the paving conjecture for triangular matrices" by
Peter G. Casazza and Janet C. Tremain.
Abstract: We resolve a 25 year old problem by showing that
The Paving Conjecture is equivalent to The Paving Conjecture for
Triangular
Matrices.
Archive classification: Functional Analysis
Mathematics Subject Classification: 47A20, 47B99, 46B07
The source file(s), 12.5.06.tex: 20512 bytes, is(are) stored in
gzipped form as 0701101.gz with size 7kb. The corresponding postcript
file has gzipped size 87kb.
Submitted from: pete(a)math.missouri.edu
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URL
http://front.math.ucdavis.edu/math.FA/0701101
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This is an announcement for the paper "On weakly extremal structures
in Banach spaces" by J. Talponen.
Abstract: This paper deals with the interplay of the geometry of
the norm and the weak topology in Banach spaces. Both dual and
intrinsic connections between weak forms of rotundity and smoothness
ared discussed. Weakly exposed points, weakly locally uniformly
rotund spaces, smoothness, duality and the interplay of all the
above are studied. An example of a Banach space, which is midpoint
locally uniformly rotund but not weakly locally uniformly rotund
is given.
Archive classification: Functional Analysis
Mathematics Subject Classification: 46B20; 46A20
Remarks: 12 pages
The source file(s), wg.tex: 45886 bytes, is(are) stored in gzipped
form as 0701009.gz with size 13kb. The corresponding postcript file
has gzipped size 103kb.
Submitted from: talponen(a)cc.helsinki.fi
The paper may be downloaded from the archive by web browser from
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http://front.math.ucdavis.edu/math.FA/0701009
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This is an announcement for the paper "Local automorphisms of the
Hilbert ball" by Bernhard Lamel.
Abstract: We prove an analogue of Alexander's Theorem for holomorphic
mappings of the unit ball in a complex Hilbert space: Every holomorphic
mapping which takes a piece of the boundary of the unit ball into
the boundary of the unit ball and whose differential at some point
of this boundary is onto is the restriction of an automorphism of
the ball. We also show that it is enough to assume that the mapping
is only Gateaux-holomorphic.
Archive classification: Complex Variables; Functional Analysis
Mathematics Subject Classification: 32H12, 46G20, 46T25, 58C10
The source file(s), L_hilbertball/definitions.tex: 3255 bytes,
L_hilbertball/hilbertball2.bbl: 1011 bytes, L_hilbertball/hilbertball2.tex:
24133 bytes, is(are) stored in gzipped form as 0612688.tar.gz with
size 10kb. The corresponding postcript file has gzipped size 89kb.
Submitted from: bernhard.lamel(a)univie.ac.at
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http://front.math.ucdavis.edu/math.CV/0612688
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