Previous Conferences & Workshops

Nov
09
2005

Joint IAS/Princeton University Number Theory Seminar

What Are Zeta Functions of Graphs and What Are They Good For?
2:00pm|Fine Hall 314

I will discuss relatively new kinds of zeta and L-functions - the Ihara-Selberg-Artin L-functions attached to finite graph coverings. In joint work with Harold Stark, we have found that many of the methods used by number theorists in investigations...

Nov
08
2005

Lie Groups, Representations and Discrete Mathematics

Spectra of Laplacians of Buildings
2:00pm|S-101

Consider an affine building of type $A_n$-tilde, which is a simplicial compex of dimension $n$. For $n=1$, this is a tree, which we will require to be homogeneous. Consider the space of complex valued functions on the vertices of the building, and...

Nov
08
2005

Computer Science/Discrete Mathematics Seminar II

Expander Graphs on the Symmetric Groups, Part II
10:30am|S-101

I will present a recent result by Martin Kassabov, which answers affirmatively a 20 year-old open question: Do the symmetric groups S_n contain bounded-size generating sets U_n such that the Cayley graphs C(S_n,U_n) are (bounded-degree) expander...

Nov
07
2005

Members’ Seminar

On some Properties of the Nottingham Group
4:00pm|S-101

Let F be a finite field. The Nottingham group N(F) is the group of formal power series \{ t(1+a_1 t + a_2 t^2 + ...): a_i \in F \}or, equivalently, the group of wild automorohisms of the local field F((t)). In spite of such a simple definition, the...

Nov
07
2005

Special Joint IAS/Princeton University Number Theory Seminar

Growth of Selmer Groups in Dihedral Extensions
Karl Rubin
2:15pm|Fine Hall 224

In joint work with Barry Mazur, we obtain lower bounds for Selmer ranks of elliptic curves over dihedral extensions of number fields, giving evidence for a generalized Parity Conjecture. Heegner points can account for large Selmer groups in dihedral...

Nov
07
2005

Computer Science/Discrete Mathematics Seminar I

Near-Optimal Algorithms for Unique Games
Yuri Makarychev
11:15am|S-101

Unique games were introduced by Uriel Feige and Laszlo Lovasz. We are given a graph G, a set of labels [k] = {1,...,k}, and permutations pi_{uv} on the set [k] (for all edges (u,v)). Our goal is to find an assignment of labels to variables x(u) (for...

Nov
04
2005

Arithmetic Homogeneous Spaces

Ergodic Theory on Simisimple Groups and Lattice Subgroups
11:00am|S-101

We will describe some recent ergodic theorems for general families of averages on semisimple Lie groups, and explain how they can be used to 1) Solve the lattice point counting problem for general domains in the group, with explicit estimate of the...

Nov
02
2005

Joint IAS/Princeton University Number Theory Seminar

Rational Homology Spheres and Automorphic Forms
Frank Calegari
2:00pm|Fine Hall 314

Let K be an imaginary quadratic field. Modular forms for K are related to the cohomology of arithmetic 3-manifolds. By using the Galois representations associated to such forms we produce an explicit tower of rational homology three spheres with...

Nov
01
2005

Lie Groups, Representations and Discrete Mathematics

Buildings and the Spectra of their Laplacians
2:00pm|S-101

Consider an affine building of type $A_n$-tilde, which is a simplicial compex of dimension $n$. For $n=1$, this is a tree, which we will require to be homogeneous. Consider the space of complex valued functions on the vertices of the building, and...

Nov
01
2005

Computer Science/Discrete Mathematics Seminar II

Expander Graphs on the Symmetric Groups
10:30am|S-101

I will present a recent result by Martin Kassabov, which answers affirmatively a 20 year-old open question: Do the symmetric groups S_n contain bounded-size generating sets U_n such that the Cayley graphs C(S_n,U_n) are (bounded-degree) expander...