Previous Conferences & Workshops

Apr
16
2009

Joint IAS/Princeton University Number Theory Seminar

Stable Topology of Hurwitz Spaces and Arithmetic Counting Problems
Jordan Ellenberg
4:30pm|Fine Hall -- 214

We will discuss some arithmetic counting problems, ranging from the antique (how many squarefree integers are there in [0 . . N]?) to the au courant (conjectures of Bhargava and Cohen-Lenstra about the distributions of discriminants and of class...

Apr
15
2009

Mathematical Physics Seminar

Spectral Dynamics and Critical Thresholds in Nonlinear Convective Equations
Eitan Tadmor
4:00pm|S-101

We discuss the global regularity vs. finite time breakdown in nonlinear convection driven by different models of forcing. Finite time breakdown depends on whether the initial configuration crosses intrinsic, O(1) critical thresholds (CT). Our...

Apr
15
2009

Mathematical Physics Seminar

Rigidity and Flexibility of $C^{1,\alpha}$ Isometric Embeddings
11:30am|S-101

A corollary of a celebrated theorem of Nash and Kuiper is the existence of $C^1$ isometric embeddings of the standard 2-sphere in arbitrarily small balls of the euclidean 3-d space. On the contrary, the image of $C^2$ isometric embeddings are all...

Apr
14
2009

Geometric PDE Seminar

On the Scattering Conjecture and Rigidity Conjecture of Mass Critical Nonlinear Schrodinger Equations
2:00pm|S-101

In this talk, I will first give an overview of recent progress on the scattering conjecture and rigidity conjecture for mass critical NLS. Then I will describe our recent results concerning both conjectures for L_2 initial data. I will also discuss...

Apr
13
2009

Computer Science/Discrete Mathematics Seminar I

Bounded Independence Fools Halfspaces
11:15am|S-101

A halfspace (a.k.a. threshold) is a boolean function h : {-1,1}^n --> {-1,1} of the form h(x) = sign(w_0 + w_1 x_1 + ... + w_n x_n), where the weights w_i are arbitrary real numbers. Halfspaces are studied extensively in the theories of complexity...

Apr
10
2009

Mathematical Physics Seminar

Renormalization Group Methods
Jon Dimock
4:00pm|S-101

This talk is about renormalization group methods for quantum field theory and classical statistical mechanics. The renormalization group is not a group but a technique for reducing infinite dimensional integrals with strong correlations to a...

Apr
08
2009

Mathematical Physics Seminar

Low-degree Landau-Lifshitz and Schroedinger Maps
Stephen Gustafson
4:00pm|S-101

The Schroedinger (and Landau-Lifshitz) map equations are a basic model in ferromagnetism, and a natural geometric (hence nonlinear) version of the Schroedinger (and Schroedinger-heat) equation. While there has been recent progress on the question of...

Apr
07
2009

Geometric PDE Seminar

A Gluing Construction for Solutions to Fully Nonlinear Equations in Conformal Geometry
Giovanni Catino
3:30pm|S-101

We construct new solutions to the $\sigma_k$-Yamabe problem on compact manifolds by considering the connected sum of two nondegenerate solutions $(M^n_1,g_1)$ and $(M^n_2,g_2)$, for any $2 \leq 2k < n$.