This is an announcement for the paper "Embedding the diamond graph in
$L_p$ and dimension reduction in $L_1$" by J. R. Lee and A. Naor.
Abstract: We show that any embedding of the level-k diamond graph of
Newman and Rabinovich into $L_p$, $1 < p \le 2$, requires distortion at
least $\sqrt{k(p-1) + 1}$. An immediate consequence is that there exist
arbitrarily large n-point sets $X \subseteq L_1$ such that any D-embedding
of X into $\ell_1^d$ requires $d \geq n^{\Omega(1/D^2)}$. This gives a
simple proof of the recent result of Brinkman and Charikar which settles
the long standing question of whether there is an $L_1$ analogue of the
Johnson-Lindenstrauss dimension reduction lemma.
Archive classification: Functional Analysis; Combinatorics; Metric
Geometry
Remarks: 3 pages. To appear in Geometric and Functional Analysis (GAFA)
The source file(s), diamond-gafa.tex: 8222 bytes, is(are) stored in
gzipped form as 0407520.gz with size 3kb. The corresponding postcript
file has gzipped size 31kb.
Submitted from: jrl(a)cs.berkeley.edu
The paper may be downloaded from the archive by web browser from URL
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This is an announcement for the paper "Strong martingale type and uniform
smoothness" by J\"org Wenzel.
Abstract: We introduce stronger versions of the usual notions of
martingale type p <= 2 and cotype q >= 2 of a Banach space X and show that
these concepts are equivalent to uniform p-smoothness and q-convexity,
respectively. All these are metric concepts, so they depend on the
particular norm in X.
These concepts allow us to get some more insight into the fine line
between X
being isomorphic to a uniformly p-smooth space or being uniformly
p-smooth itself.
Instead of looking at Banach spaces, we consider linear operators
between
Banach spaces right away. The situation of a Banach space X can be
rediscovered from this by considering the identity map of X.
Archive classification: Functional Analysis
Mathematics Subject Classification: 46B04 (Primary); 46B20, 47A63
(Secondary)
Remarks: 11 pages
The source file(s), strong.arxiv.tex: 30219 bytes, is(are) stored in
gzipped form as 0407482.gz with size 8kb. The corresponding postcript
file has gzipped size 56kb.
Submitted from: wenzel(a)minet.uni-jena.de
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/math.FA/0407482
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This is an announcement for the paper "The UMD constants of the summation
operators" by J\"org Wenzel.
Abstract: The UMD property of a Banach space is one of the most useful
properties when one thinks about possible applications. This is in
particular due to the boundedness of the vector-valued Hilbert transform
for functions with values in such a space.
Looking at operators instead of at spaces, it is easy to check that the
summation operator does not have the UMD property. The actual asymptotic
behavior however of the UMD constants computed with martingales of length
n is unknown.
We explain, why it would be important to know this behavior, rephrase
the
problem of finding these UMD constants and give some evidence of how
they behave asymptotically.
Archive classification: Functional Analysis
Mathematics Subject Classification: 46B07 (Primary); 46B03, 46B09, 47B10
(Secondary)
Remarks: 22 pages
The source file(s), umd_sumop.arxiv.tex: 64167 bytes, is(are) stored in
gzipped form as 0407481.gz with size 18kb. The corresponding postcript
file has gzipped size 85kb.
Submitted from: wenzel(a)minet.uni-jena.de
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/math.FA/0407481
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Below is the tentative schedule for SUMIRFAS 2004. The final schedule
will be posted on the Workshop in Linear Analysis and Probability page:
http://www.math.tamu.edu/research/workshops/linanalysis/
The Home Page also contains other information about the Workshop,
including a list of participants and a schedule of seminars.
Housing: Contact Cheryl Williams, cherylr(a)math.tamu.edu, or Mary Chapman,
mary(a)math.tamu.edu, (979/845-3621, office; 979/ 845-6028, fax) for help
with housing. Please specify the type of accommodation
you desire (smoking or nonsmoking), which night(s) you need the room,
and roommate preference, if applicable.
We expect to be able to cover housing, possibly in a double room,
for most participants, from support the National Science Foundation has
provided for the Workshop. Preference will be given to participants who
do not have other sources of support, such as sponsored
research grants. When you ask Cheryl or Mary to book your room, please
let them know if you are requesting support. Rooms in CS are tight the
weekend of SUMIRFAS, so please act ASAP.
Dinner: There will be a dinner at 6:30 p.m. on Saturday, August 7th,
at Imperial Chinese Restaurant,, 2232 S. Texas Ave. College Station.
The cost for the subsidized dinner is $15 per person for faculty and $10
per person for students. Please tell Cheryl Williams or Mary Chapman,
if you (and spouse or companion, if applicable) will attend.
Checks should be made out to Math Dept., TAMU.
** DINNER RESERVATIONS SHOULD BE MADE BY August 2nd and
PAYMENT MADE BY August 6th. **
Friday, August 6 Blocker 120
1:00-1:30 Coffee, Blocker 112
1:30-2:30 Uffe Haagerup, Random matrices and C*-algebras.
2:40-3:40 Taka Ozawa, New progress in the classification of group von
Neumann algebras.
3:40-4:00 Coffee, Blocker 112
4:00-4:40 Andras Zsak, The lattice of closed ideals of a dual Banach
space.
4:50-5:20 Hun Hee Lee, OH-type and OH-cotype of operator spaces and
completely summing maps.
Saturday, August 7 Blocker 120
9:00-9:30 Coffee & Donuts, Blocker 112
9:30-10:30 Michael Lacey, Hankel operators and product BMO.
10:40-11:40 Assaf Naor, Markov chains in metric spaces and the Lipschitz
extension problem.
11:50-12:20
12:20-1:40 Lunch
1:40-2:40 Hari Bercovici, A classical proof of a conformal mapping
theorem derived from free probability theory.
2:50-3:50 Alexander Koldobsky, Intersection bodies and $L_p$-spaces.
3:50-4:20 Coffee, Blocker 112
4:30-5:00 Vlad Yaskin, Busemann-Petty problem in hyperbolic and
spherical spaces.
5:10-5:40 Masayoshi Kaneda, Extreme points of the unit ball of a
quasi-multiplier space
6:30- Dinner at Imperial Chinese Restaurant, 2232 S. Texas Ave.
Sunday, August 8 Blocker 120
9:30-10:00 Coffee & Donuts, Blocker 112
10:00-11:00 Stephen Semmes, Happy fractals.
11:10-12:10 Staszek Szarek, Questions in convexity and geometry of Banach
spaces related to quantum information theory.
12:20-12:50 George Androulakis, Embedding L_infinity into the space of
all operators on certain Banach spaces.
This is an announcement for the paper "Oscillation stability of the
Urysohn metric space" by Vladimir Pestov.
Abstract: We outline general concepts of oscillation stability and
distortion for spaces with action of a topological transformation group,
and survey a number of examples. We observe that the universal Urysohn
metric space $\U$ (viewed as a homogeneous factor-space of its group of
isometries) is oscillation stable, that is, for every bounded uniformly
continuous function $f\colon\U\to\R$ and each $\e>0$ there is an isometric
copy $\U^\prime\subset\U$ of $\U$, such that $f\vert_{\U^\prime}$ is
constant to within $\e$. This stands in marked contrast to the unit sphere
$\s^\infty$ of the Hilbert space $\ell^2$, which is a universal analogue
of $\U$ in the class of spherical metric spaces, but has the distortion
property according to a well-known result by Odell and Schlumprecht.
Archive classification: Functional Analysis
Mathematics Subject Classification: 05C55; 22F30; 43A85; 46B20; 54E35;
54H15
Remarks: 10 pages, LaTeX 2e
The source file(s), osc.tex: 48054 bytes, is(are) stored in gzipped
form as 0407444.gz with size 16kb. The corresponding postcript file has
gzipped size 63kb.
Submitted from: vpest283(a)uottawa.ca
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/math.FA/0407444
or
http://arXiv.org/abs/math.FA/0407444
or by email in unzipped form by transmitting an empty message with
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uget 0407444
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This is an announcement for the paper "Dynamical entropy in Banach spaces"
by David Kerr and Hanfeng Li.
Abstract: We introduce a version of Voiculescu-Brown approximation
entropy for isometric automorphisms of Banach spaces and develop within
this framework the connection between dynamics and the local theory of
Banach spaces discovered by Glasner and Weiss. Our fundamental result
concerning this contractive approximation entropy, or CA entropy,
characterizes the occurrence of positive values both geometrically
and topologically. This leads to various applications; for example,
we obtain a geometric description of the topological Pinsker factor and
show that a C*-algebra is type I if and only if every multiplier inner
*-automorphism has zero CA entropy. We also examine the behaviour of
CA entropy under various product constructions and determine its value
in many examples, including isometric automorphisms of l_p spaces and
noncommutative tensor product shifts.
Archive classification: Functional Analysis; Dynamical Systems; Operator
Algebras
Remarks: 40 pages; subsumes the material from math.DS/0303161
The source file(s), CA13.tex: 144163 bytes, is(are) stored in gzipped
form as 0407386.gz with size 41kb. The corresponding postcript file has
gzipped size 162kb.
Submitted from: kerr(a)math.uni-muenster.de
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/math.FA/0407386
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ANNOUNCEMENT OF SUMIRFAS 2004
The Informal Regional Functional Analysis Seminar
August 6 - 8
Texas A&M University, College Station
Schedule: Talks for SUMIRFAS will be posted on the Workshop in
Linear Analysis and Probability page, URL
http://www.math.tamu.edu/research/workshops/linanalysis/
Below is a list of speakers, current as of July 18.
The Home Page also contains other information about the Workshop,
including a list of participants and a schedule of seminars.
Housing: Contact Cheryl Williams, (cherylr(a)math.tamu.edu; 979/845-9424,
office; 979/ 845-6028, fax) for help with housing. Please tell Cheryl the
type of accommodation you desire (smoking or nonsmoking).
We expect to be able to cover housing for most participants from support
the National Science Foundation has provided for the Workshop. Preference
will be given to participants who do not have other sources of support,
such as sponsored research grants. When you ask Cheryl to book your room,
please tell her if you are requesting support.
Dinner: There will be a dinner at 6:30 p.m. on Saturday, August 7, at
Imperial Chinese Restaurant, 2232 S. Texas Ave. in College Station. The
cost for the subsidized dinner is $15 per person for faculty and
accompanying
persons and $10 per person for student participants. Please tell Cheryl
Dorn if
you (and spouse or companion, if applicable) will attend. Checks should be
made out to Math. Dept., TAMU.
** DINNER RESERVATIONS SHOULD BE MADE BY August 2
and PAYMENT MADE BY August 6. **
W. Johnson, johnson(a)math.tamu.edu
K. Dykema, kdykema(a)math.tamu.edu
D. Larson, larson(a)math.tamu.edu
G. Pisier,pisier(a)math.tamu.edu
J. Zinn, jzinn(a)math.tamu.edu
SUMIRFAS talks (as of July 18)
Hari Bercovici, A classical proof of a conformal mapping theorem derived
from free probability theory
Uffe Haagerup, Random Matrices and C*-algebras
Alexander Koldobsky, Intersection bodies and $L_p$-spaces
Michael Lacey, Hankel Operators and Product BMO
Narutaka Ozawa, New progress in the classification of group von Neumann
algebras
Assaf Naor, Markov chains in metric spaces and the Lipschitz extension
problem
Stanislaw Szarek, (not yet confirmed)
This is an announcement for the paper "The Daugavet property of
$C^*$-algebras, $JB^*$-triples, and of their isometric preduals"
by Julio Becerra-Guerrero and Miguel Martin.
Abstract: A Banach space $X$ is said to have the Daugavet property if
every rank-one operator $T:X\longrightarrow X$ satisfies $\|Id + T\|
= 1 + \|T\|$. We give geometric characterizations of this property
in the settings of $C^*$-algebras, $JB^*$-triples and their isometric
preduals. We also show that, in these settings, the Daugavet property
passes to ultrapowers, and thus, it is equivalent to an stronger property
called the uniform Daugavet property.
Archive classification: Functional Analysis; Operator Algebras
Mathematics Subject Classification: Primary 17C; 46B04; 46B20; 46L05;
46L70; Secondary 46B22, 46M07
Remarks: 18 pages
The source file(s), BeceMart.tex: 68626 bytes, is(are) stored in gzipped
form as 0407214.gz with size 19kb. The corresponding postcript file has
gzipped size 90kb.
Submitted from: mmartins(a)ugr.es
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http://front.math.ucdavis.edu/math.FA/0407214
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This is an announcement for the paper "Saturating constructions for
normed spaces II" by Stanislaw J. Szarek and Nicole Tomczak-Jaegermann.
Abstract: We prove several results of the following type: given finite
dimensional normed space V possessing certain geometric property there
exists another space X having the same property and such that
(1) log(dim X) = O(log(dim V)) and (2) every subspace of X, whose dimension
is not "too small," contains a further well-complemented subspace nearly
isometric to V. This sheds new light on the structure of large subspaces
or quotients of normed spaces (resp., large sections or linear images
of convex bodies) and provides definitive solutions to several problems
stated in the 1980s by V. Milman. The proofs are probabilistic and depend
on careful analysis of images of convex sets under Gaussian linear maps.
Archive classification: Functional Analysis; Probability
Mathematics Subject Classification: 46B20; 46B07; 52A21; 52A22; 60D05
Remarks: 35 p., LATEX
The source file(s), SzarekTomczakSat2.tex: 104176 bytes, is(are) stored
in gzipped form as 0407234.gz with size 33kb. The corresponding postcript
file has gzipped size 127kb.
Submitted from: szarek(a)cwru.edu
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/math.FA/0407234
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This is an announcement for the paper "Saturating constructions for
normed spaces" by Stanislaw J. Szarek and Nicole Tomczak-Jaegermann .
Abstract: We prove several results of the following type: given finite
dimensional normed space V there exists another space X with
log(dim X) = O(log(dim V)) and such that every subspace (or quotient) of X,
whose dimension is not "too small," contains a further subspace isometric
to V. This sheds new light on the structure of such large subspaces or
quotients (resp., large sections or projections of convex bodies) and
allows to solve several problems stated in the 1980s by V. Milman. The
proofs are probabilistic and depend on careful analysis of images of
convex sets under Gaussian linear maps.
Archive classification: Functional Analysis; Probability
Mathematics Subject Classification: 46B20; 52A21; 52A22; 60D05
Remarks: 27 p., LATEX
The source file(s), SzarekTomczakSat1.tex: 71711 bytes, is(are) stored
in gzipped form as 0407233.gz with size 25kb. The corresponding postcript
file has gzipped size 105kb.
Submitted from: szarek(a)cwru.edu
The paper may be downloaded from the archive by web browser from URL
http://front.math.ucdavis.edu/math.FA/0407233
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