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Spring 2009 Seminars Schedule *
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Mondays
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Graduate-Organized Talks Seminar
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Time: 2:00-3:00pm *
Location: Cupples I, Room 199
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Host: Larry Lin
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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: Professor John McCarthy
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Tuesdays
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Algebraic Geometry Seminar
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Time: 3:00-4:30pm *
Location: Eads, Room 215
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Host: Professor Mohan Kumar
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Statistics Seminar
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Time: 4:30-5:30pm *
Location: Cupples I, Room 199
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Host: Assistant Professor Nan Lin
Statistics Seminar Schedule
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Wednesdays
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Geometry and Topology Seminar
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Time: 3:00-4:00pm *
Location: Cupples I, Room 199
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Hosts: Professor Rachel Roberts and Assistant Professor Xiang Tang
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Graduate Student Seminar
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Time: 4:00-5:00pm *
Location: Cupples I, Room 199
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Host: Professor Steven Krantz
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Thursdays
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Combinatorics and Group Theory Seminar
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Time: 12:00-1:00pm *
Location: Cupples I, Room 199
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Host: Jonathan Browder
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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: Professor Guido Weiss
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* Times may vary, please consult the schedule below for details:
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JANUARY 2009
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Monday, January 12
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Analysis Seminar
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Time:4:00-5:00pm
Location: Cupples I, Room 199
Host: Prof. John McCarthy
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Speaker: Professor John McCarthy
Department of Mathematics, Washington University in St. Louis
Title: Organizational meeting.
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Thursday, January 15
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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. Steven Krantz
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Speaker: Professor Kang-Tae Kim
Department of Mathematics, Pohang University of Science and Technology
Title: Functions holomorphic along a holomorphic vector field
Abstract: In 1977, F. Forelli proved: if a function defined on the
unit ball in complex $n$-dimensional Euclidean space is holomorphic on
every complex 1-dimensional complex line through the origin and if it
is indefinitely differentiable at the origin, then the function is
holomorphic. It was commented over the years that there seem no
significant improvements possible. E. Poletsky of Syracuse (NY) and
G. Schmalz of Armidale (Australia) and I were fortunate to be able to
link this theorem with holomorphic vector fields and Analytic
Differential Equations and then to obtain an improvement of Forelli's
theorem, which I would like to discuss in the colloquium.
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Tuesday, January 20
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Statistics Seminar
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Time:4:30-5:30pm
Location: Cupples I, Room 199
Host: Assistant Professor Nan Lin
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Speaker:Patricio S. La Rosa
Department of Electrical and Systems Engineering,
Washington University in St. Louis
Title: Detection of Uterine Magnetomyogram Contractions During Pregnancy
Abstract: In this work, we develop a novel mathematical framework for analyzing uterine contractions during pregnancy using biomagnetic measurements. We propose an automatic robust single-channel two-stage statistical detector of uterine magnetomyogram (MMG) contractions. Unlike in previous approaches, the proposed algorithm does not require the use of a sliding window of analysis and the detection threshold is determined analytically. Our algorithm is based on the assumption that the preprocessed measurements are piecewise stationary having distribution in a common family with a fixed number of parameters. In the first stage, we propose a model-based segmentation procedure, which detects multiple change-points in the parameters of a piecewise constant time-varying autoregressive model using a robust formulation of the Schwarz information criterion (SIC) and a binary search approach. In particular, we propose a test statistic that depends on the SIC, derive its asymptotic distribution, and obtain closed-form optimal detection thresholds in the Neyman-Pearson sense; therefore, we control the probability of false alarm and maximize the probability of change-point detection in each stage of the binary search algorithm. We compute and evaluate the relative energy variation [root mean squares (RMS)] in discriminating between time segments with and without contractions. Thus, in the second stage, we apply a nonsupervised K-means cluster algorithm to classify the detected time segments using the RMS values.
We apply our detection algorithm to real MMG records obtained from ten patients admitted to the hospital for contractions with gestational ages between 31 and 40 weeks. We evaluate the performance of our detection algorithm in computing the detection and false alarm rate using the patients’ feedback as a reference. When evaluated with real MMG measurements, the algorithm detected the uterine activity much earlier than the patient sensed it. It also enabled visualization of the relative location of the origin of uterine contraction and quantification of the amount of energy delivered during a contraction. These results are important in obstetrics as a tool for characterizing contractions and predicting labor.
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Thursday, January 22
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Combinatorics and Group Theory Seminar
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Time:12:00-1:00pm
Location: Cupples I, Room 199
Host: Jonathan Browder
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Speaker: Professor John Shareshian
Department of Mathematics, Washington University in St. Louis
Title: TBA
Abstract: TBA
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Monday, January 26
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Graduate-Organized Talks Seminar
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Time:2:00-3:00pm
Location: Cupples I, Room 199
Host: Larry Lin
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Speaker: Ben Manning
Department of Mathematics, Washington University in St. Louis
Title: Spectral Theorem
Abstract: An introduction to Banach algebras, Gelfand transformation,
and the spectral theorem.
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Monday, January 26
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Analysis Seminar: Minor Oral
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Time:4:00-5:00pm
Location: Cupples I, Room 199
Host: Prof. John McCarthy
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Speaker: Jeffrey Langford
Department of Mathematics, Washington University in St. Louis
Title: The ratio of the first two Dirichlet eigenvalues of the
Laplacian
Abstract: In the mid 1950's, Payne, Polya, and Weinberger began the
study bounding the quotient of the first two eigenvalues of the
Laplacian for domains of fixed size within the plane. They found a
crude estimate for the quotient, and conjectured that the quotient is
maximized when the domain in question is a disk. Later, Thompson
generalized the work of those listed above, obtaining an estimate for
domains of higher dimension. He also made a conjecture that the
quotient of eigenvalues for a ball is given in terms of zeros of
Bessel functions. In 1992, Ashbaugh and Benguria gave a full proof
that among all domains of fixed size, the eigenvalue quotient is
maximized when the domain is a ball. Moreover, the eigenvalue
quotient for a ball is given in terms of zeros of Bessel functions,
as Thompson conjectured. We sketch the proof, concentrating on the
contributions of Ashbaugh and Benguria.
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Wednesday, January 28
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Geometry and Topology Seminar
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Time:3:00-4:00pm
Location: Cupples I, Room 199
Hosts: Professor Rachel Roberts, Assistant Professor Xiang Tang
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Speaker: William Chauvenet Lecturer Rajan Mehta
Department of Mathematics, Washington University in St. Louis
Title: Introduction to Witten's approach to Jones polynomial
Abstract: TBA
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Wednesday, January 28
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Graduate Student Seminar
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Time:4:00-5:00pm
Location: Cupples I, Room 199
Host: Prof. Steven Krantz
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Speaker: William Chauvenet Lecturer Russ Woodroofe
Department of Mathematics, Washington University in St. Louis
Title: Lower bounds from topology
Abstract: I will discuss the use of results from topology to prove that combinatorial
structures are 'complicated'. I have in mind two examples. I will discuss
in detail a lower bound for the chromatic number of a graph, including a
proof of the Kneser-Lovász Theorem. If there is time, I will also sketch a
lower bound in computational complexity.
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FEBRUARY 2009
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Monday, February 2
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Graduate-Organized Talks Seminar
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Time: 2:00-3:00pm
Location: Cupples I, Room 199
Host: Larry Lin
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Speaker: Tim Lott
Department of Mathematics, Washington University in St. Louis
Title: A Knot Theory Primer
Abstract: Knots, while seemingly simple, have far-reaching
applications: they are used to study 3-manifolds, DNA, synthetic
molecules, and even statistical mechanics. In this talk, we will
discuss differing techniques (combinatorial, algebraic, and geometric)
used in knot theory, natural invariants used to distinguish knots, and
applications to other fields such as those mentioned. This talk is
specifically geared towards 1st and 2nd-year students; no knowledge
past possibly linear algebra will be required.
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Monday, February 2
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Analysis Seminar
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Time: 4:00-5:00pm
Location: Cupples I, Room 199
Host: Prof. John McCarthy
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Speaker: Professor Wing-Suet Li
School of Mathematics, Georgia Institute of Technology
Title: Horn inequalities for finite von Neumann algebras
Abstract: The Horn inequalities give a characterization of eigenvalues of
self-adjoint n by n matrices A, B, C with A+B+C=0. The original proof
by Klyachko and Knutson-Tao,
requires tools from algebraic geometry, among other things. In this talk I
will
talk about our recent result of Horn inequalities that is
valid for self-adjoint operators in arbitrary finite factors.
Since there is no readily available algebraic geometry tools
to apply to finite factors, we are forced to look for
a new proof of the original theorem for matrices, using elementary tools,
which can be extended to finite factors.
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Tuesday, February 3
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Algebraic Geometry Seminar
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Time:3:00-4:30pm
Location: Eads, Room 215
Host: Professor Mohan Kumar
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Speaker:Professor Mohan Kumar
Department of Mathematics,
Washington University in St. Louis
Title: Dao's work on bundles on hypersurfaces
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Tuesday, February 3
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Statistics Seminar
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Time:4:30-5:30pm
Location: Cupples I, Room 199
Host: Assistant Professor Nan Lin
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Speaker:Ruibin Xi
Department of Mathematics,
Washington University in St. Louis
Title: TBA
Abstract: TBA
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Wednesday, February 4
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Graduate Student Seminar
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Time:4:00-5:00pm
Location: Cupples I, Room 199
Host: Prof. Steven Krantz
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Speaker: Professor David Wright
Department of Mathematics, Washington University in St. Louis
Title: Combinatorics, power series, and inverse funtions
Abstract: We present a connection between a basic object of
combinatorics, namely the tree, and the local inverse of an analytic
function. We also show how this relates to one of the most basic
unsolved problems in function theory.
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Thursday, February 5
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Colloquium
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Time: Tea: 3:30-4:00pm
Talk: 4:00-5:00pm
Location: Cupples I, Room 199
Host: Prof. Rachel Roberts
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Speaker: Assistant Professor Josh Sabloff
Department of Mathematics, Haverford College
Title: Invariants of Legendrian Knots and the Legendrian Mirror Problem
Abstract: I will introduce a special type of 2-plane field on R^3 called the
standard contact structure. A Legendrian knot is a closed, embedded
curve that is everywhere tangent to the contact structure. Similarly
to topological knot theory, a fundamental problem in Legendrian knot
theory is to determine when it is possible -- or impossible -- to
deform one Legendrian knot into another through Legendrian knots.
One motivating question in the field asks whether a Legendrian knot
can be deformed to its "Legendrian mirror." To find a new family of
examples of Legendrian knots distinct from their Legendrian mirrors,
I will introduce a "non-classical" invariant of Legendrian knots
called Legendrian Contact Homology. The construction of the
invariant involves some neat combinatorics and results in a fertile
but complex algebraic object. I will end by indicating how the non-
commutativity of the algebra is related to the Legendrian mirror
question. This is joint work with G. Civan, J. Etnyre, P.
Koprowski, and A. Walker
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Tuesday, February 10
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Statistics Seminar
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Time:4:30-5:30pm
Location: Cupples I, Room 199
Host: Assistant Professor Nan Lin
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Speaker:Andrew Womack
Department of Mathematics,
Washington University in St. Louis
Title: TBA
Abstract: TBA
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Wednesday, February 11
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Graduate Student Seminar
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Time:4:00-5:00pm
Location: Cupples I, Room 199
Host: Prof. Steven Krantz
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Speaker: William Chauvenet Lecturer Geir Arne Hjelle
Department of Mathematics, Washington University in St. Louis
Title: TBA
Abstract: TBA
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Tuesday, February 17
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Statistics Seminar
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Time:4:30-5:30pm
Location: Cupples I, Room 199
Host: Assistant Professor Nan Lin
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Speaker:Xiao Huang
Department of Mathematics,
Washington University in St. Louis
Title: TBA
Abstract: TBA
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Wednesday, February 18
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Graduate Student Seminar
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Time: 4:00-5:00pm
Location: Cupples I, Room 199
Host: Prof. Steven Krantz
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Speaker: Associate Professor Jack Shapiro
Department of Mathematics, Washington University in St. Louis
Title: Noncommutative Differential Forms
Abstract: A classic example of commutative differential forms is based on
C^(inf)(U), the commutative R-algebra of all infinitely differential
functions on and open connected set, U, of R^n. Partial derivatives
provides the 1-forms. A. Connes and M. Karoubi generalized this to an
associative unital algebra, replacing partial derivatives with
derivations. From this they developed what is called Noncommutative
Geometry. More recently it has been shown that we can extend this to
twisted derivations, the twisting coming from some given automorphism of
the algebra. This is related to the study of Quantum groups in
Mathematical Physics.
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Thursday, February 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. Steven Krantz
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Speaker: Assistant Professor Svitlana Mayboroda
Department of Mathematics, Purdue University
Title: Harmonic analysis and elliptic equations in non-smooth domains
Abstract: Despite its long history, the theory of elliptic partial
differential
equations is abundant with open problems. We will discuss the main
achievements in the
theory, recent developments, surprising paradoxes related to the behavior
of solutions
near the boundary, and some fundamental questions which still remain open.
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Wednesday, February 25
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Graduate Student Seminar
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Time:4:00-5:00pm
Location: Cupples I, Room 199
Host: Prof. Steven Krantz
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Speaker: Professor Edward Spitznagel
Department of Mathematics, Washington University in St. Louis
Title: TBA
Abstract: TBA
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MARCH 2009
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Wednesday, March 4
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Graduate Student Seminar
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Time:4:00-5:00pm
Location: Cupples I, Room 199
Host: Prof. Steven Krantz
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Speaker: Assistant Professor Jimin Ding
Department of Mathematics, Washington University in St. Louis
Title: TBA
Abstract: TBA
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Wednesday, March 18
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Graduate Student Seminar
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Time:4:00-5:00pm
Location: Cupples I, Room 199
Host: Prof. Steven Krantz
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Speaker: Assistant Professor Nan Lin
Department of Mathematics, Washington University in St. Louis
Title: TBA
Abstract: TBA
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Thursday, March 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. Edward Wilson
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Speaker: Professor Robert Azencott
Department of Mathematics, University of Houston
Title: TBA
Abstract: TBA
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Tuesday, March 24
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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. Gary Jensen
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Speaker: Professor Robert Osserman
Mathematical Sciences Research Institute
Title: An inverse problem in the calculus of variations, tube-like domains, and compressed catenaries
Abstract: The topics covered in this talk are all connected to an attempt to understand the mathematical underpinnings of the Gateway Arch. In general terms, the shape of the Arch is a polyhedral approximation to a piecewise-smooth surface that is the boundary of a tube-like domain centered on a compressed catenary curve. All these terms and the relations among them will be explained, along with their relevance to other features of the arch, such as the size and shape of the cross sections.
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Wednesday, March 25
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Lecture
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Time: 4:00-5:00pm
Location:
Steinberg Hall Auditorium
Host: Prof. Gary Jensen
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Speaker: Professor Robert Osserman
Mathematical Sciences Research Institute
Title: How the Arch got its Shape – A Just So Story
Abstract:
What is the shape of the Gateway Arch?
A parabola? No!
A catenary? No!
A “weighted catenary”? What does that mean?
And how did the Arch get its shape?
A sketch by Saarinen?
A model?
A mathematical equation?
A building code?
Lots of questions, many with surprising answers. Another case where the truth is harder to find, and stranger than the fiction that passes for fact.
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APRIL 2009
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Thursday, April 2
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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: Assist. Prof. Jimin Ding
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Speaker: Assistant Professor Shuangge Ma
Department of Biological and Biomedical Sciences, Epidemiology and Public Health, Yale University
Title: TBA
Abstract: TBA
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Thursday, April 2
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Loeb Undergraduate Mathematics Lecture
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Tea: 3:45pm, Cupples I, Room 200
Talk: 4:30-5:30pm, January Hall, Room 110
Host: Prof. Ronald Freiwald
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Speaker: Professor Ravi Vakil
Department of Mathematics, Stanford University
Title: The Mathematics of Doodling
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Thursday, April 9
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Hirschman Lecture
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Time: Tea: 4:00-4:30pm
Talk: 4:30-5:30pm
Location: Cupples I, Room 199
Hosts: Prof. Guido Weiss, Prof. Edward Wilson
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Speaker: Professor Steve Wainger
Department of Mathematics, University of Wisconsin
Title: The circle method of Hardy,
Littlewood and Ramanujan
Abstract: Click here to view the abstract.
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Tuesday, April 14
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Statistics Seminar
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Time:4:30-5:30pm
Location: Cupples I, Room 199
Host: Assistant Professor Nan Lin
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Speaker: Chunlin Fan
Department of Mathematics,
Washington University in St. Louis
Title: TBA
Abstract: TBA
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Wednesday, April 15
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Graduate Student Seminar
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Time:4:00-5:00pm
Location: Cupples I, Room 199
Host: Prof. Steven Krantz
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Speaker: Professor Stanley Sawyer
Department of Mathematics, Washington University in St. Louis
Title: TBA
Abstract: TBA
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Thursday, April 16
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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: Assist. Prof. Jimin Ding, Assist. Prof. Nan Lin
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Speaker: Assistant Professor Ji Zhu
Department of Mathematics, University of Michigan
Title: TBA
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Tuesday, April 21
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Statistics Seminar
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Time:4:30-5:30pm
Location: Cupples I, Room 199
Host: Assistant Professor Nan Lin
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Speaker: Haley Abel
Department of Mathematics,
Washington University in St. Louis
Title: TBA
Abstract: TBA
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Thursday, April 23
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Annual Department Awards Ceremony
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Time: Tea: 4:00-4:30pm, Ceremony: 4:30-6:00pm
Location: Cupples I, Room 199
Host: Professor Ronald Freiwald
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Awards to mathematics faculty, graduate students, undergraduate students, ... , and more.
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