Previous Special Year Seminar

Mar
07
2007

Complex Algebraic Geometry

Canonical Frames for Nonholonomic Vector Distributions
Igor Zelenko
1:00pm|S-101

The talk is based on the joint work with Boris Doubrov. First we will describe a new rather effective procedure of symplectification for the problem of local equivalence of nonholonomic vector distributions. The starting point of this procedure is...

Mar
01
2007

Motivic Cohomology

Bass' NK Groups and cdh-Fibrant Hochschild Homology
11:00am|S-101

By definition, NK_0(R) is K_0(R[t]) modulo K_0(R). We give a formula for this group when R is of finite type over a field of characteristic zero. The group is bigraded and determined by its typical pieces, which are the cdh cohomology groups H^p(R...

Feb
22
2007

Motivic Cohomology

Arithmetic Cohomology and Special Values of Zeta-Functions (after Geisser)
11:00am|S-101

Geisser gives conjectured formulas for special values of zeta-functions of varieties over finite fields in terms of Euler characteristics of arithmetic cohomology (an improved version of Weil-etale cohomology). He then proves these formulas under...

Feb
13
2007

Motivic Cohomology

The Syntomic Regulator for K_1 of Surfaces
2:00pm|S-101

We give an explicit formula for the syntomic regulator of certain elements in the first algebraic K-theory group of a smooth complete surface over the ring of integers of a p-adic field. The formula uses the theory of Coleman integration and the...

Feb
06
2007

Motivic Cohomology

An Approach to the Conservation of the Nearby Motive Functor
2:00pm|S-101

We present a program to prove the following conjecture: Let $S$ be the spectrum of a DVR of equi-characteristic zero with field of fraction $K$ and residue field $k$. The functor (associated to the choice of a uniformizing) $\Psi:DM_{gm}(K) \to DM_...

Dec
14
2006

Birational Geometry

Finite Generation VI: Moduli Spaces
2:00pm|S-101

We will finish the sketch of the proof of existence of a geometrically meaningful compactification of the moduli space of canonically polarized smooth varieties.

Dec
13
2006

Complex Algebraic Geometry

Parabolic Chern Character of the de Rham Bundles
11:00am|S-101

Characteristic classes of Flat bundles on smooth algebraic varieties are defined in various cohomology theories. We consider the de Rham cohomology, the Deligne cohomology and the rational Chow groups and study the classes. We focus on the special...

Dec
07
2006

Complex Algebraic Geometry

Witten Equation and Singularity Theory
Yongbin Ruan
12:00pm|S-101

In 1991, Witten proposed a famous conjecture (solved by Kontsevich) related the intersection theory of Deligne-Mumford moduli space to KDV-integrable hierearchy. To generalize his conjecture, Witten proposed a remarkable PDE based any...