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University of Georgia
Department of Mathematics

Seminar Schedule
August 28 - September 1, 2006

All Seminars are held in Boyd Graduate Studies Bldg. unless otherwise noted.

MONDAY, August 28, 2006

Topology
2:30pm, Room 304
Speaker: John Etnyre, Georgia Institute of Technology
Title of talk: Contact structures and foliations.
Abstract: In the min 1990's Eliashberg and Thurston proved that any foliation (apart from the foliation of S2 X S1 by S2's) can be perturbed into a contact structure. This has had major implications in contact geometry and low dimensional topology over the last few years. After surveying some of the past work in this area I will discuss a recent observation that all contact structures are perturbations (even deformations) of foliation. This result follows form Giroux's connection between open book decompositions of 3-manifolds and contact structures and some simple constructions and computations.

4:00-5:00 pm, Room 304
Speaker: Skander Zannad, University of Nantes, France
Title of talk: Laminations, branched surfaces and contact structures.
Abstract : Laminations are an intermediate between surfaces and foliations. In particular, essential laminations generalize both incompressible surfaces and tight foliations. The main topological result about essential laminations, is that the universal cover of a manifold of dimension 3 carrying an essential lamination is $\mathbb{R}^3$. To study laminations, branched surfaces appear to be useful objects. In this talk, we will give a sufficient condition for a branched surface to fully carry a lamination, giving a piece of answer to a problem D. Gabai.

In an attempt to link the theory of contact structures to the theory of branched surfaces and laminations, we give a sufficient condition so that two contact structures forming a pair are carried by the same branched surface. We will see how this result may be used to get topological results.

Algebra
2:30pm, Room 410
Speaker: Victor Kreiman, University of Georgia
Title of talk: An Equivariant Littlewood-Richardson Rule
Abstract: We describe Knutson-Tao's equivariant Littlewood-Richardson rule, which is expressed in terms of puzzles. We give an equivalent form of the rule in terms of tableaux and an explicit bijection between the two models. We discuss an independent proof of the tableau rule which extends a proof by Stembridge of the ordinary Littlewood-Richardson rule.

Faculty and Graduate Social
3:00pm, Room 409
Coffee, Tea, Cookies

TUESDAY, August 29, 2006

VIGRE Graduate Student Seminar
2:00pm, Room 302
Speaker: Maxim Arap, University of Georgia
Title of talk: An Introduction to the Poincare Conjecture
Abstract: The presentation is going to begin with the statement of Poincare conjecture. Afterwards, the presenter will try to introduce some of the topological notions which are needed to understand the statement of Poincare conjecture. Examples illustrating various concepts, definitions, and theorems will be provided.

Faculty and Graduate Social
3:00pm, Room 409
Coffee, Tea, Cookies

Departmental Meeting
3:30pm, Room 304

Analysis
3:30pm, Room 222
No Meeting this week


WEDNESDAY, August 30, 2006

Special Applied Mathematics Seminar
1:30-2:30pm, Room 322
Speaker: Phil Bording, Husky Energy Chair in Oil and Gas Research, University of Newfoundland
Title of talk: Images of the Elastic Earth
Abstract: Dr. Bording will discuss the exploration of the three- dimensional interior of the earth with elastic waves. Like ultrasound images of the body, seismic images of the earth allow us to explore without the shovel or drill bit. The lecture will contain examples from exploration of the Grand Banks for their deposits of natural gas and oil.

Algebraic Geometry
2:30pm, Room 410
Speaker: G. Michael Guy, University of Georgia
Title of talk: Moduli of weighted stable maps and their gravitational descendants, Part 2.
Abstract. We study the intersection theory on the moduli spaces of maps of $n$-pointed curves $f:(C,s_1,... s_n)\to V$ which are stable with respect to a weight data $(a_1,..., a_n)$, $0\le a_i\le 1$. After describing the structure of these moduli spaces, we prove a formula describing the way each descendant changes under a wall crossing. As a corollary, we compute the weighted descendants in terms of the usual ones, i.e. for the weight data $(1,...,1)$, and vice versa. (Based on a joint work with V. Alexeev.)

Faculty and Graduate Social
3:00pm, Room 409
Coffee, Tea, Cookies

Arithmetic Geometry/Number Theory

3:30pm, Room 304
Speaker: Pete Clark, University of Georgia
Title of talk: An attempt at a parallel introduction to (some) quaternionic Shimura curves.
Abstract: This talk will also be purely expository. Although I will attempt to keep things as elementary as possible, one necessarily has to mention things like quaternion algebras and endomorphism rings of abelian surfaces, so may be appropriate for more advanced graduate students (and beyond).


THURSDAY, August 31, 2006


Wavelets and Splines
2:30pm, Room 524
No Meeting this week

VIGRE-Algebraic Geometry
2:00pm, Room 326
Organizational Meeting


FRIDAY, September 1, 2006

Probability Theory
2:30pm, Room 323
Speaker: Q. Zhang, University of Georgia
Title of talk: HJB equations and verification theorems

Geometry
2:30pm, Room 410
Speaker: Ted Ashton, University of Georgia
Title of talk: A Brief Introduction to Tensegrity Theory
Abstract: Kenneth Snelson (http://www.kennethsnelson.net) is a sculptor who works with aluminum bars and steel cable to build very beautiful, mathematical sculptures. His work is based on a concept called "tensegrity". In this talk I will introduce the idea of a Tensegrity Framework from the 1981 paper Tensegrity Frameworks by Roth and Whitely and explore the ideas of rigidity and flexibility of tensegrity frameworks. The talk is intended to be accessible to undergraduates.

VIGRE-Algebra
2:30pm, Room 304