# Seminars & Events for 2009-2010

December 10, 2009
3:00pm - 5:00pm
##### Periodicity and Duality
###### Algebraic Topology Seminar

This talk will produce periodic families of Poincare duality spaces, giving a partial answer to a problem posed in the proceedings of the 1982 Northwestern homotopy theory conference. The ideas will also relate James Periodicity to the four-fold periodicity of the surgery obstruction groups.

Speaker: John Klein, Wayne State University
Location:
Fine Hall 1203
December 10, 2009
4:30pm - 6:30pm
##### Bundle structures and Algebraic K-theory
###### Topology Seminar

This talk will describe (Waldhausen type) algebraic K-theoretic obstructions to lifting fibrations to fiber bundles having compact smooth/topological manifold fibers.The surprise will be that a lift can often be found in the topological case. Examples will be given realizing the obstructions.

Speaker: John Klein, Wayne State University
Location:
Fine Hall 314
December 10, 2009
4:30pm - 6:30pm
##### An effective proof of the Oppenheim Conjecture
###### Princeton University/IAS Number Theory Seminar

In the mid 80's Margulis proved the Oppenheim Conjecture regarding values of indefinite quadratic forms. I will present new work, joint with Margulis, where we quantify this statement by giving bounds on the size of integer vectors for which $|Q(x)|<\epsilon$ for an irrational indefinite quadratic form $Q$ in three variables.

Speaker: Elon Lindenstrauss, Princeton University
Location:
IAS Room S-101
December 11, 2009
2:00pm - 4:00pm
##### Diophantine Properties of Dynamical Systems and IETs
###### Ergodic Theory & Statistical Mechanics

The lecture is based on a recent preprint with the same title, joint with J. Chaika and put recently on arXiv. One of the results is that for ergodic IETs (Interval Exchange Transformations) almost sure $\liminf_{n\to\infty} n|T^nx-y|=0$.

Speaker: Michael Boshernitzan, Rice University
Location:
Fine Hall 401
December 11, 2009
3:00pm - 5:00pm
##### Uniqueness of constant scalar curvature Kähler metrics
###### Differential Geometry & Geometric Analysis Seminar

We will show that constant scalar curvature Kähler(cscK) metric "adjacent" to a given Kähler class is unique up to isomorphism. This generalizes the previous uniqueness theorems of Chen-Tian and Donaldson, where the complex structure is fixed. Joint work with X-X. Chen.

Speaker: Song Sun, University of Wisconsin
Location:
Fine Hall 314
December 14, 2009
5:00pm - 7:00pm
##### Radiation field for Einstein Vacuum equations
###### Analysis Seminar
Speaker: Fang Wang, MIT
Location:
Fine Hall 110
December 16, 2009
4:30pm - 6:30pm
##### Ideas around Symplectic Field Theory
###### Department Colloquium

Symplectic Field Theory (SFT) is the study of (pseudo-)holomorphic curves in symplectic cobordisms and contains Gromov-Witten theory and symplectic Floer theory as special cases. The algebraic invariants of SFT are obtained by a simultaneous study of infinitely many interdependent first order elliptic systems which exhibit compactness and transversality issues.

Speaker: Helmut Hofer, IAS
Location:
Fine Hall 314
December 17, 2009
2:00pm - 4:30pm
##### The k edge-disjoint paths problem in digraphs with bounded independence number
###### Discrete Mathematics Seminar

In 1980, Fortune, Hopcroft, and Wyllie showed that the following algorithmic problem (k-EDP) is NP-complete with $k=2$: k Edge-Disjoint Paths (k-EDP) Instance: A digraph $G$, and $k$ pairs $(s_1,t_1),...,(s_k,t_k)$ of vertices of $G$.

Question: Do there exist directed paths $P_1,...,P_k$ of $G$, mutually edge-disjoint, such that $P_i$ is from $s_i$ to $t_i$ for $i=1,...,k$?

Speaker: Alexandra Ovetsky Fradkin, Princeton University
Location:
Fine Hall 224
December 17, 2009
4:30pm - 6:30pm
##### Bordered Floer homology and factoring mapping classes
###### Topology Seminar

I will discuss "bordered Floer homology", an invariant for three-manifolds with parameterized boundary. The theory associates a differential graded algebra to a (parameterized) surface; and a module over that algebra to a three-manifold which bounded by the surface.

Speaker: Peter Ozsvath, Columbia University
Location:
Fine Hall 314
January 14, 2010
10:00am - 11:00am
##### A Phase transition for a model of Random band matrices
###### Department Colloquium

Miniconference on Dynamical Systems at Princeton

Speaker: Thomas Spencer, Princeton University
Location:
January 14, 2010
11:00am - 12:00pm
##### Zero temperature limits of Gibbs states
###### Department Colloquium

Miniconference on Dynamical Systems at Princeton

Speaker: Michael Hochman, Princeton University
Location:
January 14, 2010
2:00pm - 3:00pm
##### Escape rates and variational principles for dynamical systems with holes
###### Department Colloquium

Miniconference on Dynamical Systems at Princeton

Speaker: Mark Demers, Princeton University
Location:
January 14, 2010
3:00pm - 4:00pm
##### Progress on Affine Sieves
###### Department Colloquium

Miniconference on Dynamical Systems at Princeton

Speaker: Alex Kontorovich, Princeton University
Location:
January 14, 2010
4:30pm - 5:30pm
##### The Mobius function, randomness and dynamics
###### Department Colloquium

Miniconference on Dynamical Systems at Princeton

Speaker: Peter Sarnak, Princeton University
Location:
January 15, 2010
9:30am - 10:30am
##### The Full Renormalization Horseshoe for Unicritical Maps, revisited
###### Department Colloquium

Miniconference on Dynamical Systems at Princeton

Speaker: Mikhail Lyubich, Princeton University
Location:
January 15, 2010
11:00am - 12:00pm
##### Geometry and Topology of Chaotic Transport
###### Department Colloquium

Miniconference on Dynamical Systems at Princeton

Speaker: John Delos, Princeton University
Location:
January 15, 2010
12:00pm - 1:00pm
##### On Arnold diffusion in arbitrary degrees of freedom and an almost dense orbit on energy surface
###### Department Colloquium

Miniconference on Dynamical Systems at Princeton

Location:
January 15, 2010
2:30pm - 3:00pm
##### Ergodicity of some open systems with particle-disk interactions
###### Department Colloquium

Miniconference on Dynamical Systems at Princeton

Speaker: Tanya Yarmola, Princeton University
Location:
January 15, 2010
3:00pm - 3:30pm
##### Lyapunov exponents, periodic orbits and horseshoes in infinite dimensional systems
###### Department Colloquium

Miniconference on Dynamical Systems at Princeton

Speaker: Zeng Lian, Princeton University
Location: