Joint IAS/PU Number Theory

Mod p Points on Shimura Varieties

Mark Kisin
Harvard University
March 8, 2012

A conjecture of Langlands-Rapoport predicts the structure of the mod p points on a Shimura variety. The conjecture forms part of Langlands' program to understand the zeta function of a Shimura variety in terms of automorphic L-functions.

I will report on progress towards the conjecture in the case of Shimura varieties attached to non-exceptional groups.

Arithmetic Fake Compact Hermitian Symmetric Spaces

Gopal Prasad
University of Michigan
February 16, 2012
A fake projective plane is a smooth complex projective algebraic surface whose Betti numbers are same as those of the complex projective plane but which is not the complex projective plane. The first fake projective plane was constructed by David Mumford in 1978 using p-adic uniformization. This construction is so indirect that it is hard to obtain geometric properties of the fake projective plane. A major problem in the theory of complex algebraic surfaces was to find all fake projective planes in a way which allows us to discover their geometric properties.

On Real Zeros of Holomorphic Hecke Cusp Forms and Sieving Short Intervals

Kaisa Matomäki
University of Turku, Finland
October 13, 2011

A. Ghosh and P. Sarnak have recently initiated the study of so-called real zeros of holomorphic Hecke cusp forms, that is zeros on certain geodesic segments on which the cusp form (or a multiple of it) takes real values. In the talk I'll first introduce the problem and outline their argument that many such zeros exist if many short intervals contain numbers whose all prime factors belong to a certain subset of primes. Then I'll speak about new results on this sieving problem which lead to improved lower bounds for the number of real zeros.

Serre's Conjectures on the Number of Rational Points of Bounded Height

Per Salberger
Chalmers University of Technology
April 28, 2011

JOINT IAS/PU NUMBER THEORY SEMINAR

We give a survey of recent results on conjectures of Heath-Brown and Serre on the asymptotic density of rational points of bounded height. The main tool in the proofs is a new global determinant method inspired by the local real and p-adic determinant methods of Bombieri-Pila and Heath-Brown.