Seminar Calendar
for events the day of Friday, September 26, 2008.

.
events for the
events containing

More information on this calendar program is available.
Questions regarding events or the calendar should be directed to Tori Corkery.
     August 2008           September 2008          October 2008
Su Mo Tu We Th Fr Sa   Su Mo Tu We Th Fr Sa   Su Mo Tu We Th Fr Sa
1  2       1  2  3  4  5  6             1  2  3  4
3  4  5  6  7  8  9    7  8  9 10 11 12 13    5  6  7  8  9 10 11
10 11 12 13 14 15 16   14 15 16 17 18 19 20   12 13 14 15 16 17 18
17 18 19 20 21 22 23   21 22 23 24 25 26 27   19 20 21 22 23 24 25
24 25 26 27 28 29 30   28 29 30               26 27 28 29 30 31
31


Friday, September 26, 2008

Women in Mathematics
12:00 pm   in 148 Henry,  Friday, September 26, 2008
 Del Edit Copy
Submitted by ctsai6.
 Valerie Peterson (UIUC Math)Robots and cube complexes: a geo-group-ological perspective Abstract: A variety of settings in manufacturing, robotics, biology, chemistry and other areas suggest a need to coordinate moving agents in some optimal fashion. In this talk, I'll introduce a cube complex that records independent moves in many 'reconfigurable systems' and helps determine optimal paths for motion (or at least helps us keep our robots from colliding). I will also present some interesting geometric, topological and group theoretic properties of these complexes. This talk has been designed with undergraduates in mind but I hope it will be entertaining for those from a wide variety of backgrounds.

Graduate Student Topology & Geometry Seminar
1:00 pm   in Altgeld Hall 141,  Friday, September 26, 2008
 Del Edit Copy
Submitted by nstaple2.
 Rosona Eldred (Department of Mathematics, University of Illinois)Goodwillie Calculus, Totalization and maybe Segal Abstract: Over the summer, I talked about the setup for my research project. This could be viewed as an extension of that talk. No pre-requisites expected.

Model Theory and Descriptive Set Theory
4:00 pm   in 347 Altgeld Hall,  Friday, September 26, 2008
 Del Edit Copy
Submitted by vlopes2.
 Tobias Kaiser (University of Regensburg, Germany)Hilbert 16, the Riemann Mapping Theorem, the Dirichlet problem, and o-minimalityAbstract: We investigate the connection of o-minimality and the following three concepts from analysis. 1. Hilbert's 16th Problem: What can be said about the number of limit cycles of a polynomial vector field in the plane? 2. The Riemann Mapping Theorem: A proper simply connected domain in the plane can be mapped biholomorphically onto the unit ball. 3. The Dirichlet problem: The following PDE with boundary value problem is considered. Given a domain U and a continuous boundary function h the Dirichlet solution for h is harmonic in U and can be continuously extended by h to the boundary of U. Important tools in the work on Hilbert 16 are Poincare return maps resp. transition maps at singular boundary points of the vector field. In the context of the Riemann Mapping Theorem we are interested in the case that the domain is globally semianalytic. In the context of the Dirichlet problem we are interested in the case that the domain is in the plane and that both domain and boundary function are globally semianalytic. The main result is the following. There is an o-minimal structure such that transition maps at non-resonant hyperbolic singular points, the Riemann map and the Dirichlet solution (under an additional condition on the angles at singular boundary points in both cases) are definable in this structure. In the first part of the talk we introduce the three concepts from analysis. A key step in Ilyashenko's work on Hilbert 16 is the introduction of a certain quasianalytic class in which transition maps at hyperbolic singularities live. We show that both the Riemann map and the Dirichlet solution (with semianalytic raw data) can also be realized in this quasianalytic class. In the second part we show how we obtain an o-minimal structure from this quasianalytic class. The main difficulty is the right definition of the quasianalytic classes in several variables. In the third part we discuss further developments in this direction. (This talk is sequel to the one in the Logic seminar on Tuesday Sept. 23rd.)

Seminar on Sheaves of Dimension 1
4:00 pm   in 241 Altgeld Hall,  Friday, September 26, 2008
 Del Edit Copy
Submitted by choi29.
 Jinwon Choi   [email] (Department of Mathematics, University of Illinois)Gromov-Witten theory and Donaldson-Thomas theoryAbstract: I will introduce the Gromov-Witten theory and the Donaldson-Thomas theory of Calabi-Yau threefolds. These two theories are conjectured to be equivalent. The conjecture is proven for local Calabi-Yau toric surfaces by computing Donaldson-Thomas invariants using the virtual localization. The main reference for this talk is Maulik, Nekrasov, Okounkov and Pandharipande, Gromov-Witten Theory and Donaldson-Thomas theory, I. (math/0312059v3)