Seminar Schedule
October 15 - October 19, 2007
All Seminars are held in Boyd Graduate Studies Bldg. unless otherwise noted.
MONDAY, October 15, 2007
Algebra2:30pm, Room 410
Speaker: Kenyon Platt, University of Georgia
Title of talk: Non-empty Blocks of Parabolic Category \mathcal{O}_S
Abstract: For a set S of simple roots of a complex simple Lie algebra g,The parabolic category \mathcal{O}_S decomposes as a direct sum of subcategories, called infinitesimal blocks of \mathcal{O}_S, such that each module in \mathcal{O}_S decomposes into the direct sum of modules where each summand belongs to one of the infinitesimal blocks. One of the first questions to ask is when is a given infinitesimal block non-empty. This question will take us into the realm of nilpotent orbits of g, whereRichardson orbits will play a key role in the answer.
Topology
2:30pm, Room 303
Speaker: Clint McCrory, University of Georgia
Title of talk: Orbifolds and wallpaper patterns, part 3
Abstract: I will prove the Gauss-Bonnet Theorem for 2-dimensionalorbifolds and use it to classify wallpaper patterns, following Thurston and Conway.
Faculty and Graduate Social
3:00pm, Room 409
Coffee, Tea, Cookies
TUESDAY, October 16, 2007
VIGRE - Graduate Student Seminar
2:00pm, Room 304
Speaker: Andrew Sornborger, University of Georgia
Title: Multivariate Statistical Optimization Analysis of Ratiometric Imaging Data
Abstract: In the biological imaging context, ratiometric fluorescent indicators have seen a recent surge in application due to the ability of fluorescence ratios to eliminate illumination variability and bleaching artifacts and to give quantitative estimates of variables of interest. A typical problem with ratiometric indicators is that taking ratios of noisy fluorescence measurements from two channels can result in poor ratio estimation. In this talk, I will discuss ratio estimates in imaging data. Our methods are generally applicable to a wide range of ratiometric indicators including voltage sensitive dyes, calcium dyes and genetically encoded FRET indicators such as cameleon.
FRG Analysis and Additive Combinatorics Working Group
3:30pm, Room 410
Speaker: Akos Magyar, University of Georgia
Title of talk: On Szemeredi's (unpublished) improvement of the bound inRoth's theorem
WEDNESDAY, October 17, 2007
Algebraic Geometry2:30pm, Room 410
Speaker: Valery Alexeev (UGA)
Title of talk: Canonical limits of varieties
Abstract: This is going to be a colloquium-style lecture, for non-experts.Does a one-parameter family of (say, algebraic) varieties have a canonical limit? The answer depends on the category in which they are considered. For embedded projective varieties there are three different approaches: varieties as cycles (van der Waerden), subschemes (Grothendieck), and varieties with a finite map (joint with Knutson), which lead to three different moduli spaces: Chow variety, Hilbert scheme, or moduli ofbranchvarieties.For non-embedded varieties the Minimal Model Program gives the canonical limits, higher-dimensional generalizations of the Deligne-Mumford-Knudson-Kontsevich stable curves and maps. I will review several cases of special interest (Calabi-Yau varieties, etc.)Tropical geometry gives a simplified picture of one-parameter degenerations. Using the above examples, I will explain what it captures and what it misses.
Faculty and Graduate Student Social
3:00pm, Room 409
Coffee, Cookies, Tea
Arithmetic Geometry/Number Theory
3:30pm, Room 304
Speaker: Patrick Corn, University of Georgia
Title of talk: Tate-Shafarevich groups of genus-2 Jacobians
Abstract: Let C be a genus-2 curve over a number field k, with Jacobian J.Just as for genus-1 curves, the mysterious part of the 2-Selmer group of J is the 2-torsion in Sha(J). I'll sketch two possible constructions (the second of which is new) of examples of C for which this 2-torsion is nontrivial, using Brauer-Manin obstructions on certain K3 surfaces.
Mathematical Physics3:45pm, Room 302
Speakers: Brad Bassler and Robert Varley, University of Georgia
Title of talk: Caratheodory's formulation of thermodynamics
THURSDAY, October 18, 2007
VIGRE Algebraic Geometry
3:30pm, Room 323
Applied Math2:00pm, Room 302
Speaker: Qianying Hong, University of Georgia
Title of talk: PDE Methods for Image Analysis
Abstract: Recently, Partial Differential Equations(PDE) have been successfully applied to study image analysis and produced many interesting and exciting results. They shows that PDE is a powerful and extremely useful tool for image analysis. In the talk, I will give an introduction of several famous PDE models for image analysis including noise removing and edge enhancing. Also, if time allows, I will talk about the idea of level set and total and edge enhancing. Also, if time allows, I will talk about the idea of level set and total variation in image analysis.
VIGRE Tropical Geometry
2:00pm, Room 304
VIGRE Circle Packing
3:30pm, Room 222
VIGRE-Number Theory
2:30pm, Room 326
FRIDAY, October 19, 2007
VIGRE-Algebra
1:30pm, Room 302
Geometry
2:30pm, Room 410
Speaker: TBA
Title of talk: TBA