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FALL 2009 Seminars Schedule
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Mondays
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Analysis Seminar
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Time: 4:00-5:00pm *
Location: Cupples I, Room 199
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Host: Prof. Richard Rochberg
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Tuesdays
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Combinatorics Seminar
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Time: 2:00-3:00pm *
Location: Cupples I, Room 199
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Host: Russ Woodroofe
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Graduate Organized Talks Seminar
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Time: 4:00-5:00pm *
Location: Cupples I, Room 199
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Host: Raphiel Murden
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Wednesdays
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Graduate Students Talk
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Time: 3:00-4:00pm *
Location: Cupples I, Room 199
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Host: Prof. Guido Weiss
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Algebraic Geometry Seminar
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Time: 4:00-5:30pm *
Location: Cupples I, Room 215
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Host: Prof. Mohan Kumar
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Thursdays
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Geometry and Topology Seminar
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Time: 3:00-4:00pm *
Location: Cupples I, Room 111
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Host: Prof. Xiang Tang
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Fridays
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Wavelet Seminar
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Time: 3:30-4:30pm *
Location: Cupples I, Room 199
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Host: Prof. Guido Weiss
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* Times may vary, please consult the schedule below for details:
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NOVEMBER 2009
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Monday, November 2
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Analysis Seminar
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Time: 4:00-5:00pm
Location: Cupples I, Room 199
Host: Prof. Richard Rochberg
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Speaker: Professor Marcus Carlsson
Department of Mathematics, Purdue University
Title: Approximation of functions by sums of (few) exponentials and
AAK-theory for Hankel operators
Abstract: An algorithm from 2004 by G. Beylkin and L. Monzon aimed at
achieving the first part of the title, is shown to be a consequence
of the
Adamyan Arov Krein theorem on finite rank approximations of Hankel
operators, (at least for certain cases). The algorithm does however
work
in greater generality than the current theory supports. I will
introduce
various operators that in one way or another deserves the name Hankel
operator, present new results about these as well as open problems.
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Tuesday, November 3
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Combinatorics Seminar
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Time: 2:00-3:00pm
Location: Cupples I, Room 199
Host: Russ Woodroofe
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Speaker: Professor John Shareshian
Department of Mathematics, Washington University in St. Louis
Title: Intervals in subgroup lattices of finite groups
Abstract: Continuation of last week's seminar.
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Tuesday, November 3
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Graduate Organized Talks Seminar
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Time: 4:00-5:00pm
Location: Cupples I, Room 199
Host: Raphiel Murden
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Speaker: Ben Manning
Department of Mathematics, Washington University in St. Louis
Title: TBA
Abstract: Some stuff about wavelets. If there is time, I might prove a theorem.
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Wednesday, November 4
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Colloquium
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Time: Tea: 4:00-4:30pm
Talk: 4:30-5:30pm
Location: Cupples I, Room 199
Host: Prof. Roya Beheshti-Zavareh
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Speaker: Professor Dragos Oprea
Department of Mathematics, University of California, San Diego
Title: Generalized theta functions
Abstract: For any compact Riemann surface, we can associate an algebraic
torus, the Jacobian, together with a theta divisor given by the zero locus
of an explicit function, the theta function. In higher rank and over an
arbitrary base, one obtains theta divisors and generalized theta functions
over moduli spaces of vector bundles. I will explain recent results
concerning the spaces of generalized theta functions.
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Friday, November 6
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Wavelet Seminar
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Time: 3:30-4:30pm
Location: Cupples I, Room 199
Host: Prof. Guido Weiss
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Speaker: Professor Hrvoje Sikic
Department of Mathematics, University of Zagreb, Croatia
Title: Systems of translates
Abstract: The study of systems of translates comes
naturally within the general wavelet framework. It
provides, among other things, an interesting connection
between harmonic and functional analysis. Working
with several people from the (world wide) St.Louis
group we have solved some and encountered some
more interesting problems.
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Monday, November 9
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Analysis Seminar
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Time: 4:00-5:00pm
Location: Cupples I, Room 199
Host: Prof. Richard Rochberg
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Speaker: Professor Jeremy Chapman
Department of Mathematics, University of Missouri, Columbia
Title: K-point configurations in vector spaces over finite fields
Abstract: Click here
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Tuesday, November 10
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Graduate Organized Talks Seminar
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Time: 4:00-5:00pm
Location: Cupples I, Room 199
Host: Raphiel Murden
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Speaker: Jeffrey Langford
Department of Mathematics, Washington University in St. Louis
Title: Theorems of Talenti-Type
Abstract: We begin by considering a PDE with arbitrary geometry and then
perform a symmetrization process to consider a "symmetrized" PDE.
Depending on which symmetrization we've used, we'll get different
relationships between the solutions. Sobolev Spaces, weak solutions
to Elliptic PDE, and Symmetrization will all be discussed.
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Thursday, November 12
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Geometry and Topology Seminar
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Time: 3:00-4:00pm
Location: Cupples I, Room 111
Host: Prof. Xiang Tang
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Speaker: Philip Huling
Department of Mathematics, Saint-Louis University
Title: Rigidity of Hyperbolic 3-Orbifolds
Abstract: We define a hyperbolic $n$-orbifold to be the quotient of hyperbolic
$n$-space, ${\mathbb H}^n$, by a discrete subgroup, $\Gamma$, of
$\text{Isom}({\mathbb H}^n)$. If $\Gamma$ is cofinite in $\text{Isom}
({\mathbb H}^3)$, then the size of its deformation space (up to conjugation)
is well known. However, we may view $\Gamma$ as being a subset of $\text
{Isom}({\mathbb H}^4)$ to investigate how this inclusion into a higher
dimension allows for more deformations in the group. We find the dimension
of the deformation space of a large class of cofinite Coxeter groups and
then develop tools to analyze the deformation space of groups commensurable
with them. Specifically, we are able to describe the deformation spaces of
those Bianchi groups which have a finite index Coxeter subgroup.
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Tuesday, November 17
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Combinatorics Seminar
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Time: 2:00-3:00pm
Location: Cupples I, Room 199
Host: Russ Woodroofe
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Speaker: Scott Cook
Department of Mathematics, Washington University in St. Louis
Title: Card Shuffling
Abstract: Since the 1990 revelation of the (deceptively nicknamed) "Seven
Shuffles is Sufficient" result in the New York Times, there has been a
flurry of activity in the mathematics of card shuffling. I'll discuss the
most widely studied shuffling model (the Gilbert-Shannon-Reeds model),
describe the methods that leads to the seven shuffles conclusion, and show
how card shuffling can be recast in the language of random walks on
hyperplane arrangements.
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Tuesday, November 17
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Graduate Organized Talks Seminar
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Time: 4:00-5:00pm
Location: Cupples I, Room 199
Host: Raphiel Murden
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Speaker: Qing Li
Department of Mathematics, Washington University in St. Louis
Title: Some basic discussions on splines
Abstract: Splines has been a classical tool in data smoothing. In this talk,
we will talk about some basic properties of cubic splines, including the
natural cubic spline and smoothing spline. In particular, how the natural
cubic spline comes into a restricted maximization problem. We will also talk
about the B-spline if time allows. This is going to be an introductory talk.
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Thursday, November 19
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Geometry and Topology Seminar
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Time: 3:00-4:00pm
Location: Cupples I, Room 111
Host: Prof. Xiang Tang
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Speaker: Professor Rachel Roberts
Department of Mathematics, Washington University in St. Louis
Title: An introduction to Heegaard Floer homology I
Abstract: TBA
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Thursday, November 19
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Colloquium
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Time: Tea: 4:00-4:30pm
Talk: 4:30-5:30pm
Location: Cupples I, Room 199
Host: Prof. Nan Lin
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Speaker: Professor Yuhong Yang
School of Statistics, University of Minnesota
Title: Combining Quantile Regression Estimators
Abstract: Model selection for quantile regression is often a challenging problem.
In addition to the well-known general difficulty of model selection
uncertainty, when
quantiles at multiple probability levels are of interest, typically a single
candidate does not serve all of them well simultaneously. In this talk
we propose methods
to combine quantile estimators. Oracle inequalities show that at each
given probability level, the combined estimators automatically perform
nearly as well as the best candidate. Simulation and real examples
show that the proposed model combination approach often leads to a
substantial gain in accuracy under global
measures of performance. (The talk is based on joint work with Kejia Shan.)
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Monday, November 23
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Analysis Seminar
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Time: 4:00-5:00pm
Location: Cupples I, Room 199
Host: Prof. Richard Rochberg
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Speaker: Jeff Langford
Department of Mathematics, Washington University in St. Louis
Title: TBA
Abstract: TBA
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Monday, November 30
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Analysis Seminar
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Time: 4:00-5:00pm
Location: Cupples I, Room 199
Host: Prof. Richard Rochberg
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Speaker: Nic Sedlock
Department of Mathematics, Washington University in St. Louis
Title: Bounded interpolation of truncated Toeplitz operators
Abstract: A truncated Toeplitz operator with a bounded symbol is
bounded, but not every bounded truncated Toeplitz operator has a
bounded symbol. I will present an example of a bounded truncated
Toeplitz operator without a bounded symbol, and discuss some extra
conditions on a bounded truncated Toeplitz operator to ensure that it
has a bounded symbol.
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DECEMBER 2009
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Tuesday, December 1
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Combinatorics Seminar
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Time: 2:00-3:00pm
Location: Cupples I, Room 199
Host: Russ Woodroofe
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Speaker: Scott Cook
Department of Mathematics, Washington University in St. Louis
Title: Card Shuffling, Part II
Abstract: Since the 1990 revelation of the (deceptively nicknamed) "Seven Shuffles is Sufficient" result in the New York Times, there has been a flurry of activity in the mathematics of card shuffling. I'll discuss the most widely studied shuffling model (the Gilbert-Shannon-Reeds model), describe the methods that leads to the seven shuffles conclusion, and show how card shuffling can be recast in the language of random walks on hyperplane arrangements.
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Wednesday, December 2
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Graduate Students Talk
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Time: 4:00-5:00pm
Location: Cupples I, Room 199
Host: Prof. Guido Weiss
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Speaker: Prof. Al Baernstein
Department of Mathematics, Washington University in St. Louis
Title: The Stretch Conjecture
Abstract: We propose a 2-variable calculus inequality involving
integrals of partial derivatives of maps from the plane into itself.
Truth of the the conjecture implies the truth of a famous conjecture
in complex and harmonic analysis. Falsity of the conjecture implies
the truth of a famous conjecture in calcules of variations.
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Thursday, December 3
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Geometry and Topology Seminar
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Time: 3:00-4:00pm
Location: Cupples I, Room 111
Host: Prof. Xiang Tang
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Speaker: Professor Rachel Roberts
Department of Mathematics, Washington University in St. Louis
Title: An introduction to Heegaard Floer homology II
Abstract: TBA
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Thursday, December 3
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Colloquium
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Time: Tea: 4:00-4:30pm
Talk: 4:30-5:30pm
Location: Cupples I, Room 199
Hosts: Prof. David Wright
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Speaker: Professor Arno van den Essen
Department of Mathematics, University of Nijmegen
Title: A Journey through Magic Squares
Abstract: Magic squares are one of the oldest mathematical objects. Found in various cultures, they have been studied by mathematicians
and laymen for over five thousand years.
In this lecture we will take a journey through the extensive
history of these squares: We will discuss normal magic squares,
pan magic squares, prime magic squares, alpha-magic squares, and
Benjamin Franklin's magic squares. We will give special attention to a
method for constructing Franklin's squares that led to a magic square craze in the Netherlands in 2007.
The lecture is aimed at a general mathematical audience. All students are encouraged to attend.
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Friday, December 4
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Wavelet Seminar
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Time: 3:30-4:30pm
Location: Cupples I, Room 199
Host: Prof. Guido Weiss
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Speaker: Brody Johnson
Department of Mathematics, Washington University in St. Louis
Title: Quincunx wavelets on the torus
Abstract: Finite-dimensional wavelet systems will be examined on the torus
using a dilation
operation which downsamples the Fourier transform of a function by the
Quincunx matrix. A
notion of multiresolution analysis is studied and examples modeled after the
classical Shannon
and Haar MRAs will be presented.
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Friday, December 4
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Colloquium
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Time: Tea: 4:00-4:30pm
Talk: 4:30-5:30pm
Location: Cupples I, Room 199
Host: Prof. Roya Beheshti-Zavareh
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Speaker: Professor Joseph Landsberg
Department of Mathematics, Texas A&M
Title: Some algebraic geometry useful for signal processing, statistics
and complexity theory
Abstract: In many areas of science one needs to measure properties of tensors. Two
important such properties are the rank and border rank. In this talk I
will explain some of the geometry of these properties. (Relevant
geometric objects are the secant varieties of Segre varieties).
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SPRING 2010 Seminars Schedule
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JANUARY 2010
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Thursday, January 21, 2010
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Colloquium
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Time: Tea: 4:00-4:30pm
Talk: 4:30-5:30pm
Location: Cupples I, Room 199
Hosts: Prof. Mohan Kumar
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Speaker: Professor Karl Schwede
Department of Mathematics, University of Michigan
Title: TBA
Abstract: TBA
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MARCH 2010
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Thursday, March 25, 2010
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Colloquium
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Time: Tea: 4:00-4:30pm
Talk: 4:30-5:30pm
Location: Cupples I, Room 199
Hosts: Profs. Al Baernstein, Guido Weiss
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Speaker: Professor Rodrigo Bañuelos
Department of Mathematics, Purdue University
Title: TBA
Abstract: TBA
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APRIL 2010
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Thursday, April 8, 2010
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Colloquium
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Time: Tea: 4:00-4:30pm
Talk: 4:30-5:30pm
Location: Cupples I, Room 199
Hosts: Prof. Quo-Shin Chi
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Speaker: Professor Yng-Ing Lee
Department of Mathematics, National Taiwan University
Title: TBA
Abstract: TBA
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Wednesday, April 14, 2010
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Colloquium
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Time: 4:00-5:00pm
Location: TBA
Hosts: Profs. David Wright, Ken Kelton, Ram Cowsik
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Speaker: Professor Srinivasa Varadhan
Courant Institute of Mathematical Sciences, New York University
Title: TBA
Abstract: TBA
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Thursday, April 15, 2010
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Colloquium
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Time: Tea: 4:00-4:30pm
Talk: 4:30-5:30pm
Location: Cupples I, Room 199
Host: Prof. Al Baernstein
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Speaker: Professor Terry Sheil-Small
Department of Mathematics, University of York, England
Title: TBA
Abstract: TBA
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Thursday, April 22, 2010
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Loeb Undergraduate Lecture in Mathematics
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Time: Tea: 4:00-4:30pm
Talk: 4:30-5:30pm
Location: TBA
Host: Prof. Ronald Freiwald
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Speaker: Professor Martin Golubitsky
Department of Mathematics and Director of the Mathematical
Biosciences Institute, Ohio State University
Title: Symmetries and Animal Gaits
Abstract: Many gaits of four-legged animals can be described by
spatio- temporal symmetries. For example, when a horse paces it moves
both left legs in unison and then both right legs and so on. The
motion is
described by two symmetries: Interchange front and back legs, and
swap left and right legs with a half-period phase shift.
Biologists postulate the existence of a central pattern generator
(CPG) in the
neuronal system that sends periodic signals to the legs. CPGs can
be thought of as electrical circuits that produce periodic signals
and can be modeled by coupled systems of differential equations
with
symmetries based on leg permutation. In this lecture we discuss
animal gaits; describe how periodic solutions with prescribed spatio-
temporal symmetry can be formed in symmetric systems; construct a
CPG
architecture that naturally produces quadrupedal gait rhythms; and
make several testable predictions about gaits.
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Thursday, April 29, 2010
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Roever Colloquium
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Time: Tea: 4:00-4:30pm
Talk: 4:30-5:30pm
Location: Cupples I, Room 199
Host: Prof. Quo-Shin Chi
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Speaker: Professor Simon Brendle
Department of Mathematics, Stanford University
Title: TBA
Abstract: TBA
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Friday, April 30, 2010
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Roever Seminar
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Time: 3:00-4:00pm
Location: Cupples I, Room 199
Host: Prof. Quo-Shin Chi
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Speaker: Professor Simon Brendle
Department of Mathematics, Stanford University
Title: TBA
Abstract: TBA
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