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Fall 2008 Seminars Schedule
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Mondays
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Graduate-Organized Talks Seminar
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Time: 3:00-4:00pm *
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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Algebraic Geometry Seminar
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Time: 4:00-5:30pm *
Location: Cupples I, Room 111
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Host: Professor Mohan Kumar
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Tuesdays
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Symplectic Geometry and Topology Seminar
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Time: 4:00-5:00pm *
Location: Cupples I, Room 216
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Host: Professor Xiang Tang
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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: Professor Jimin Ding
Statistics Seminar Schedule
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Wednesdays
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Graduate Student Seminar
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Time: 4:00-5:00pm, pizza *
Location: Cupples I, Room 199
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Host: Professor Steven Krantz
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Thursdays
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Topology Seminar
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Time: 10:00-11:00am *
Location: Cupples I, Room 199
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Host: Professor Rachel Roberts
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Combinatorics and Group Theory Seminar
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Time: 3:30-4:30pm *
Location: Eads, Room 209
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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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OCTOBER 2008
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Wednesday, October 2
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Topology Seminar
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Time:10:00-11:00am
Location: Cupples I, Room 199
Host: Prof. Rachel Roberts
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Speaker: Professor Rachel Roberts
Department of Mathematics, Washington University in St. Louis
Title: The Curve Complex
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Friday, October 3
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Colloquium
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Time:Talk: 4:30-5:30pm
Location: Cupples I, Room 199
Host: Prof. Jack Shapiro
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Speaker: Professor Jack Sonn
Technion–Israel Institute of Technology
Title: Abelian extensions of global fields with all local degrees equal to n and the n-torsion subgroup of the Brauer group
Abstract: Let K be a global field, n a positive integer. Then there exists
an abelian extension L/K whose local degree at every finite place of K
equals n and whose local degree at every real place of K equals 2 when n is
even. It follows that the n-torsion subgroup of the Brauer group of K
equals the relative Brauer group Br(L/K). (Joint work with Hershy
Kisilevsky)
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Monday, October 6
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Graduate-Organized Talks Seminar
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Time:3:00-4:00pm
Location: Cupples I, Room 199
Host: Larry Lin
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Speaker: Andrew Lewis
Department of Mathematics, Washington University in St. Louis
Title: Tame and Wild Automorphisms in Three Variables
Abstract: Tame and Wild Automorphisms in Three Variables
Abstract: The Jung-van der Kulk theorem established that all polynomial
automorphisms over a field in two variables are tame. In 1972, Nagata
conjectured that in three variables there exist non-tame, or wild
automorphisms. We will define and discuss tame and wild automorphisms,
and the recent proof of Shestakov and Umirbaev that Nagata's example is
indeed wild. We will define and discuss some of the tools they use in
this proof, such as embedding the polynomial ring inside a free Poisson
algebra. We will skip all the messy details and attempt to give a general
idea of how these tools are used. This talk will be accessible to all
grad students.
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Tuesday, October 7
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Symplectic Geometry and Topology Seminar
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Time: 4:00-5:00pm
Location: Cupples I, Room 216
Host: Assist. Prof. Xiang Tang
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Speaker: Visisting Assistant Professor Jae Hyouk Lee
Department of Mathematics, University of Missouri, St. Louis
Title: Introduction to the Moduli space of J-holomorphic curves
Abstract: J-holomorphic curves and their moduli space are key objects in the study of
symplectic topology. In this talk, we introduce the moduli space of
J-holomorphic curves and discuss the fundamental issues on it.
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Wednesday, October 8
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Algebraic Geometry Seminar
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Time: 4:00-5:30pm
Location: Cupples I, Room 111
Host: Prof. Mohan Kumar
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Speaker: Professor Hsian-hua Tseng
Department of Mathematics, University of Wisconsin
Title: Hodge integrals on Hurwitz spaces and Gromov-Witten theory of
orbifolds
Abstract: Inside moduli spaces of stable pointed curves one can consider
loci which parameterizes curves that admit Hurwitz cover structures to
over curves. These loci are called Hurwitz loci. Hurwitz-Hodge integrals
are by definition integrals over these loci of Chern classes of suitably
defined Hodge bundles. Hurwitz-Hodge integrals arise naturally as
Gromov-Witten invariants of local orbifolds. In this talk we'll review the
definition of Hurwitz-Hodge integral. We'll discuss a result, proven with
Paul Johnson and Rahul Pandharipande, which expresses cyclic Hurwitz-Hodge
integrals with one Hodge class as double Hurwitz numbers.
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Wednesday, October 8
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Graduate Student Seminar
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Time: 4:00-5:00pm, pizza
Location: Cupples I, Room 199
Host: Prof. Steven Krantz
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Speaker: Professor Renato Feres
Department of Mathematics, Washington University in St. Louis
Title: Billiards, random walks, and diffusion processes on the real line
Abstract: Motivated by applied problems concerning diffusion of gases
we introduce a class of random dynamical systems derived
from billiard maps and study certain random walks on the
real line obtained from those systems.
This talk will explore the interplay between
the deterministic billiard dynamic, stochastic properties of the
random billiard, and spectral properties of a transition
probabilities operator canonically associated with the billiard geometry.
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Thursday, October 9
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Analysis Seminar
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Time: 12:00-1:00pm
Location: Cupples I, Room 199
Host: Prof. Nick Weaver
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Speaker: Professor Charles Akemann
Department of Mathematics, University of California, Santa Barbara
Title: The Kadison-Singer Problem for Factors
Abstract:
Let N be a factor von Neumann algebra, and let A be a maximal
abelian *subalgebra of N.
QUESTION. Does every pure state of A have a unique pure state
extension to N?
SOME ANSWERS AND MANY OPEN QUESTIONS: If N is type I or II_1,
A has separable predual and A is non-atomic, then the answer
is "no". For other types of factors, I am not sure. If A is
atomic, the answer is not known (this is the original
Kadison-Singer Problem). When A does not have a separable
predual, I have no answers. When the answer is "no" and we
then ask, which pure states do not have unique extensions,
I have no answers.
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Monday, October 13
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Graduate-Organized Talks Seminar
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Time: 3:00-4:00pm
Location: Cupples I, Room 199
Host: Larry Lin
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Speaker: Larry Lin
Department of Mathematics, Washington University in St. Louis
Title: The Singular Value Decomposition
Abstract:Decomposition Theorems for matrices serve an important role
in understanding linear transformations. In this talk we talk about
one of the most important decomposition: the Singular Value
decomposition. We will explore what this decomposition is tells you ,
give some applications, and consider extensions to separable Hilbert
Spaces. This talk will assume familiarity with linear algebra and a
general interest in mathematics.
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Monday, October 13
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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: Larry Lin
Department of Mathematics, Washington University in St. Louis
Title: Triangular Truncations of Hankel Operators
Abstract: It is a consequence of the boundedness of the Bilinear
Hilbert Transform that the triangular truncation of Hankel Operators
on the Hardy space is bounded if and only if the Hankel Operator is
bounded.The first goal of this talk is to give a brief overview as to
why this is true. Natural questions to ask include whether this is
true on other spaces or on subclasses of Hankel Operators. We give
answers to the first question in the case of the Bergman space and
explore what is known in the case when one considers trace class
Hankel operators.
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Monday, October 13
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Algebraic Geometry Seminar
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Time: 4:00-5:30pm
Location: Cupples I, Room 111
Host: Prof. Mohan Kumar
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Speaker: Professor A. Prabhakar Rao
Department of Mathematics, University of Missouri, St. Louis
Title: Vector Bundles on Projective Spaces
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Tuesday, October 14
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Symplectic Geometry Seminar
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Time: 4:00-5:00pm
Location: Cupples I, Room 216
Host: Assist. Prof. Xiang Tang
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Speaker: Safdar Quddus
Department of Mathematics, Washington University in St. Louis
Title: Introduction to Symplectic fibration
Abstract: In this talk, we will explain the definition of symplectic
fibration and conditions for its existence. In particular, we will look at
this definition and condintions on the example of S^2-bundles. If time
permits, we will also introduce the concept of symplectic connection and
discuss its properties.
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Tuesday, October 14
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Statistics Seminar: Major Oral Presentation
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Time: 4:30-5:30pm
Location: Cupples I, Room 199
Host: Assist. Prof. Jimin Ding
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Speaker: Ruibin Xi
Department of Mathematics, Washington University in St. Louis
Title: Statistical Aggregation of U-statistics in Massive Data Sets
Abstract: With the development of modern technology, massive data sets become
more and more prevalent. While massive data sets contain valuable
information, their volume makes many traiditional statistical methods
computationally inapplicable. Statistical aggregation is a general
strategy to conquer such difficulty posed by massive data sets. Using this
strategy, we have successfully developed algorithms that allow fast and
efficient statistical analysis of massive data sets, such as regression
analysis.
In this talk, we will discuss the application of this strategy to
U-statistics in massive data sets. U-statistics, as an important family of
nonparametric estimator, have many desirable theoretical properties such
as unbiasedness and asymptotic normality. However, their applications in
modern statistical analysis have been limited due to the high
computational complexity. We developed two surrogates of U-statistics,
AU-statistics and AAU-statistics, both of which are asymptotically
equivalent to the U-statistics and computationally much more efficient.
The merit of these two new techniques will be demonstrated by both
simulation and real data examples.
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Wednesday, October 15
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Graduate Student Seminar
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Time: 4:00-5:00pm, pizza
Location: Cupples I, Room 199
Host: Prof. Steven Krantz
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Speaker: Professor Guido Weiss
Department of Mathematics, Washington University in St. Louis
Title: The Zac Transform
Abstract: The Zac transform was introduced some forty years ago in order to study
some properties of the Uncertainty Principle. It turns out that it can be
used to develop the basic properties of Fourier Series, Fourier Integrals
and their relation. I will show why this is true.
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Thursday, October 16
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Combinatorics and Group Theory Seminar
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Time: 3:30-4:30pm
Location: Eads, Room 209
Host: Jonathan Browder
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Speaker: Scott Cook
Department of Mathematics, Washington University in St. Louis
Title: TBA
Abstract: TBA
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Monday, October 20
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Graduate-Organized Talks Seminar
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Time: 3:00-4:00pm
Location: Cupples I, Room 199
Host: Larry Lin
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Speaker: Joe Bohanon
Department of Mathematics, Washington University in St. Louis
Title: An Introduction to Permutation Groups
Abstract: Permutation groups were a useful tool in group theory even before
the notion of an abstract group was defined. We will see how every group
can be seen as a permutation group. We will also define certain families of
permutation groups and see how they might be classified.
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Monday, October 20
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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: The Krzyz Conjecture: Part II (of, I hope III, with some help from the audience ....)
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Monday, October 20
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Algebraic Geometry Seminar
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Time: 4:00-5:30pm
Location: Cupples I, Room 111
Host: Prof. Mohan Kumar
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Speaker: Professor A. Prabhakar Rao
Department of Mathematics, University of Missouri, St. Louis
Title: Vector Bundles on Projective Spaces
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Monday, October 20
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Math Club Lecture
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Time: 5:15-6:00pm, pizza
Location: Cupples I, Room 199
Host: Prof. John McCarthy
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Speaker: Joe Bohanon
Department of Mathematics, Washington University in St. Louis
Title: Adventures in Group Theory
Abstract: Groups are one of the most fundamental tools in mathematics,
showing up in nearly every field. Abstractly, a group is a set with a
binary relation that satisfies certain axioms which we will define. We will
look at groups that show up naturally, specifically the group that lies
underneath a Rubik's cube. It turns out that solving the Rubik's cube is
more-or-less equivalent to a special case of the "word problem". No prior
knowledge of group theory is necessary for this talk.
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Tuesday, October 21
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Symplectic Geometry Seminar
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Time: 4:00-5:00pm
Location: Cupples I, Room 216
Host: Prof. Xiang Tang
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Speaker: Safdar Quddus
Department of Mathematics, Washington University in St. Louis
Title: Introduction to symplectic fibration II
Abstract: We will talk about connections,
gauge transformation, hamiltonian fibration and a last major theorem
relating all the previous result.
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Wednesday, October 22
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Graduate Student Seminar
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Time: 4:00-5:00pm, pizza
Location: Cupples I, Room 199
Host: Prof. Steven Krantz
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Speaker: Professor Mohan Kumar
Department of Mathematics, Washington University in St. Louis
Title: Matrix Factorization
Abstract: If $f$ is a polynomial in $n$ variables, one can ask whether it can be
factored in the ring of matrices over the polynomial ring, $R$. In
other words, does there exist two matrices $M,N\in M_n(R)$ for some
$n$ so that $f \mathrm{Id}_{n\times n}=MN$? Of course, some
non-triviality conditions have to be imposed to avoid for example,
writing $f=f\cdot 1$. We will discuss problems arising out of
algebraic geometry in this situation.
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Thursday, October 23
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Topology Seminar
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Time: 10:00-11:00am
Location: Cupples I, Room 199
Host: Prof. Rachel Roberts
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Speaker: Professor David Futer
Department of Mathematics, Temple University
Title: Cusp volume of fibered 3-manifolds
Abstract: Consider a 3-manifold M that fibers over the circle, with fiber a
punctured surface F. I will discuss some recent results that relate the
volume of a maximal cusp of M (in the hyperbolic metric) to combinatorial
properties of the arc complex of the fiber surface F. These results can be
applied to estimate the volume of closed 3-braids.
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Thursday, October 23
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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. Rachel Roberts
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Speaker: Professor David Futer
Department of Mathematics, Temple University
Title: From combinatorics to geometry for knots and 3-manifolds
Abstract: Powerful theorems of Thurston, Perelman, and Mostow tell us that
almost every 3-manifold admits a hyperbolic metric, and that
this metric is unique. Thus, in principle, there is a 1-to-1 correspondence
between a combinatorial description of a 3-manifold and its geometry. On the
other hand, only in the last couple of years have we begun to see the
outlines of a concrete dictionary between combinatorial features and
geometric measurements. In this vein, I will survey some recent results that
explicitly relate the combinatorics of a knot diagram to geometric features
of the knot complement and related closed 3-manifolds.
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Monday, October 27
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Graduate-Organized Talks Seminar
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Time: 3:00-4:00pm
Location: Cupples I, Room 199
Host: Larry Lin
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Speaker: Baili Min
Department of Mathematics, Washington University in St. Louis
Title: Divisors and the Riemann Roch Theorem
Abstract: For a compact Riemann surface M, we can define divisors on it which
form a group and they can be partially ordered. Consequently each
non-zero meromorphic function on M determines a divisor, and so does
each non-zero meromorphic differential. Now given an arbitrary
divisor D, we have two vector spaces: L(D), space of meromorphic
functions whose divisors are greater or equal to D, and \Omega(D),
space of abelian differentials whose divisors are greater or equal to
D. Then Riemann-Roch Theorem states a relation between the dimension
of L(D^(-1)) and dimension of \Omega(D) in terms of the degree of D
and the genus of M. This theorem is very important in the theory of
Riemann surfaces.
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Monday, October 27
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Algebraic Geometry Seminar
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Time: 4:00-5:30pm
Location: Cupples I, Room 111
Host: Prof. Mohan Kumar
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Speaker: Professor A. Prabhakar Rao
Department of Mathematics, University of Missouri - St. Louis
Title: Vector Bundles on Projective Spaces
Abstract: TBA
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Tuesday, October 28
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Symplectic Geometry and Topology Seminar
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Time: 4:00-5:00pm
Location: Cupples I, Room 216
Host: Assist. Prof. Xiang Tang
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Speaker: Professor Quo-Shin Chi
Department of Mathematics, Washington University in St. Louis
Title: Symplectic blowup
Abstract: I will review the blowup in algebraic geometry and give a snapshot
of the classification of minimal models of algebraic surfaces. This will
provide an ideal motivation for introducing the symplectic blowup and
related issues in symplectic geometry.
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Tuesday, October 28
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Statistics Seminar
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Time: 4:30-5:30pm
Location: Cupples I, Room 199
Host: Assist. Prof. Jimin Ding
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Speaker: Professor Stanley Sawyer
Department of Mathematics, Washington University in St. Louis
Title: Counting Processes and Asymptotic Theory in Survival Analysis
Abstract: Chapter 5 in Kalbfleish and Prentice's book,
The Statistical Analysis of Failure Time Data.
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Wednesday, October 29
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Graduate Student Seminar
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Time: 4:00-5:00pm, pizza
Location: Cupples I, Room 199
Host: Prof. Steven Krantz
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Speaker: Professor Gary Jensen
Department of Mathematics, Washington University in St. Louis
Title: The Bonnet problem
Abstract: In a memoire published in 1867, Pierre Ossian Bonnet considered
the problem of whether a surface could be immersed into Euclidean space in
two noncongruent ways so that the induced metrics and the mean curvatures
are the same for the two immersions. Subsequently, many people have worked
on this problem, including Elie Cartan (1942), S-S. Chern (1985), A. Bobenko
(1999), and E. Musso and me (2008). I'll describe the main features of the
problem, present some new global results, show pictures of some interesting
solutions (made by Joey Hutchings, a senior math major here), and describe
some open problems.
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Thursday, October 30
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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. Xiang Tang
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Speaker: Professor Guoliang Yu
Department of Mathematics, Vanderbilt University
Title: Geometric complexity and the stable Borel conjecture
Abstract: A fundamental problem in topology is the Borel conjecture
on rigidity of manifolds. In this talk, I will explain how a notion
of geometric complexity can be used to study a stable version of the
Borel conjecture. This is joint work with Erik Guentner and Romain
Tessera. This talk will be accessible to general audience including
graduate students.
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