University of Georgia
Department of Mathematics

Seminar Schedule
April 26 - April 30, 2004

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

MONDAY, April 26, 2004

VIGRE - Algebra
2:30p.m., Room 410
Organizer: Daniel Nakano, University of Georgia
Activity: We will look at other cases of exceptional Lie algebra involving our conjecture (i.e. G_2 p=3 and possibly F_4). We will also report on the status of some type D (p=2) calculations.

Topology
2:30p.m., Room 322
Speaker:
Will Kazez, University of Georgia
Title of talk:
"Right veering homeomorphisms of surfaces"
Abstract: I will discuss some relationships between open book decompositions, homeomorphisms of surfaces, and the class of homeomorphisms mentioned in the title.

Faculty and Graduate Social
3:00p.m., Room 409
Coffee, Cookies, Tea

Special Geometry Seminar
3:30p.m., Room 322
Speaker:
David Bao, University of Houston
Title of talk:
Curvature in Finsler geometry
Abstract: This talk has three goals. First, I would like to illustrate the ubiquitous nature of Finsler metrics. Second, the notion of flag curvature will be explained and contrasted with the sectional curvature of Riemannian metrics. Finally, the Ricci curvature will be defined, together with a discussion of Einstein-Finsler metrics.

Lie Theory
3:30p.m., Room 303
No Meeting this week

Stochastic Processes
3:30p.m., Room 410
Speaker:
Billy Jackson, University of Georgia
Title of talk:
Stability of SDEs
Abstract:
We will consider some perturbations of SDEs by using the usual techniques of stability analysis.


TUESDAY, April 27, 2004

Special Double VIGRE Graduate Student Seminar
2:00p.m., Room 304
Speaker:
Vladimir Temlyakov, University of Georgia
Title of talk:
On mathematical foundations of numerical integration
Abstract:
The main goal of this talk is to demonstrate connections between the following three big areas of research: the theory of cubature formulas (numerical integration), discrepancy theory, and nonlinear approximation. We will discuss a relation between results on cubature formulas and on discrepancy. In particular, we will show how the standard in the theory of cubature formulas settings can be translated into the discrepancy problem and into a natural generalization of the discrepancy problem. This leads to a concept of r-discrepancy. We will present results on a relation between the construction of an optimal cubature formula with m knots for a given function class and the best nonlinear m-term approximation of a special function determined by the function class. The nonlinear m-term approximation is taken with regard to a redundant dictionary also determined by the function class. We will also discuss some known results on lower and upper estimates of errors of optimal cubature formulas for special classes of functions. We will formulate some open problems in the area.

3:15p.m., Room 303
Speakers: Tanya Cofer and Pat Wilson, University of Georgia, Math Education
Title of talk: The Graduate Certificate in Mathematics Education

Special Seminar in Analysis
2:00-4:00p.m., Ga Tech, Rm. 255
Speaker: TBA
Title of talk: TBA

Wavelet Analysis
2:00p.m., Room 326
Speaker: O. Cho, University of Georgia
Title of talk: Construction of Prewavelets in Sobolev spaces

WEDNESDAY, April 28, 2004

Berkovich Spaces Seminar
11:00a.m., Room 410
Organizers: Matthew Baker and Robert Rumely

Algebra
2:30p.m., Room 410
Speaker:
Radu Stancu, Ohio-State University
Title of talk:
Control of the Fusion in Fusion Systems
Abstract: The fusion systems are a generalization of the $p$-local structure of a finite group $G$, where $p$ is a prime dividing the order of the group $G$. They were introduced by Puig in 1990. In 2000 Broto, Levi and Oliver identified and studied a certain class of spaces which in many ways behave like $p$-completed classifying spaces of finite groups. They showed that
these spaces occur as the ``classifying spaces" of fusion systems. Usingthis approach they proved the conjecture of Mislin that the homotopy type of the $p$-completed classifying space of a finite group is determined by its $p$-local structure. A fusion system is a category on a finite $p$-group $P$, whose objects are the subgroups of $P$ and whose set morphisms between any two objects $Q$, $R$ are a set of injective group homomorphisms between $Q$ and $R$, satisfying some axioms. The purpose of this talk is to give some results on the control of the fusion in a fusion system on $P$ by the automorphisms in the fusion system of a subgroup $Q$ of $P$.

Algebraic Geometry Seminar
2:30p.m., Room 303
Speaker:
TBA
Title of talk: TBA

Faculty and Graduate Social
3:00p.m., Room 409
Coffee, Cookies, Tea

Numerical Analysis
3:30p.m., Room 303
No Meeting this week

Number Theory
*Please note time and room change

2:30 - 3:30 PM Room 222
Speaker: Skip Garibaldi, Emory University
Title of talk: The Rost invariant and the Hasse principle
Abstract: Several classical local-global results for number fields (Hasse-Minkowski Theorem, Eichler's Norm Theorem) are
special casses of the Hasse principle for simply connected linear algebraic groups (like SL_n and Spin) over number fields. In the late 1990s, the Hasse principle was shown to hold for a many more fields than just number fields. This talk will present the Rost invariant, which can be viewed as a further generalization of the Hasse principle.


THURSDAY, April 29, 2004

VIGRE - Cardiac Physiology
2:30p.m., Room 322
Speaker:
TBA
Title of talk: TBA

VIGRE - Contact Topology
2:00p.m., Room 410
Organizer: Gordana Matic, University of Georgia

Faculty and Graduate Social
3:00p.m., Rom 409
Coffee, Cookies, Tea

Colloquium
3:30p.m., Room 304
Speaker:
Prof. Steve Xu , University of Tennessee at Chattanooga
Title of talk:
Evolutional properties and characteristic patterns of a mathematical model of breast cancer
Abstract:
Ductal carcinoma in situ (DCIS) refers to a specific diagnosis of cancer that is isolated within the breast duct, and has not spread to other parts of the breast. In this talk we discuss a free boundary problem model in a cylinder, a model mimicking the growth of a ductal carcinoma in situ (DCIS). As tumour growth strongly depends upon the availability of nutrients, its diffusion through the growth material is introduced in the description of model. We study the characteristic stationary solutions of the model, and compare them with the patterns found in DCIS. We also study the evolution solution and the growth of the DCIS.

Student Number Theory

3:30p.m., Room 303
Speaker: Eric Pine, University of Georgia
Title of talk: Visual Cryptography
Abstract: Everyone has heard of the RSA crypto system. Well, the "S" from RSA, Adi Shamir, has developed a new type of cryptography. This system has the advantage that anyone with two hands and eyes (and the key of course) will be able to decrypt the message. No modular arithmetic. No fancy computers needed. This talk will be very easy to understand, and
yet should also provide ideas to interest people both with and without a math background.


FRIDAY, April 30, 2004

CATS
1:25-2:15pm, Room 306
Speaker: TBA
Title of talk: TBA

Faculty and Graduate Social
*Please note change in time
2:00p.m., Rom 409
Coffee, Cookies, Tea

Electrodynamics Seminar
2:30p.m., Room 322
Speaker: Mukul Patel, University of Georgia
Title of talk: The path integral method of quantization

Geometry
2:30p.m., Room 326
Speaker: Jason Cantarella, University of Georgia
Title of talk: Animation, asteroids and tumbling bodies.
Abstract: In this talk, aimed at a student audience, we'll discuss the classical "asteroid problem": how does a body rotate or spin in the absence of annoying external forces such as gravity? We'll pay particular attention
to the problem of visualizing these motions with computer animation.

Lie Theory
2:30p.m., Room 304
Speaker:
Radha Kessar, The University of Ohio
Title of talk:
Shintani descent and perfect isometries for blocks of finite general linear groups.
Abstract: Shintani descent gives a correspondence between the set of ordinary irreducible characters of a finite general linear group GL(n,q) and a certain subset of irreducible characters of GL_n(q^d). Building on results of Watanabe, we show that under some natural conditions, this correspondence yields perfect isometries between the unipotent blocks (in cross characteristic) of the two groups. This provides another instance of the generic nature of the modular representation
theory of finite groups of Lie type.

Colloquium
3:30p.m., Room 304
Speaker:Markus Linckelmann, The Ohio State University
Title of talk: Modular representation theory and topology: some interactions
Abstract: Classical cohomology theories, such as Hochschild cohomology of the group algebra of a finite group G on the representation theoretic side, and G-equivariant Bredon cohomology on the topological side, can be viewed as particular cases of a common construction. Applications include a reformulation, in terms of Bredon cohomology, of Alperin's weight conjecture, one of the most prominent open conjectures in modular representation theory which is originally a numerical conjecture on the number of simple modules of a group algebra kG over a field of positive characteristic p in terms of the p-local structure of G.