Seminars Sorted by Series

Analytic and Geometric Number Theory Mini-Course

Apr
14
2010

Analytic and Geometric Number Theory Mini-Course

Artin's Conjecture on Zeros of p-Adic Forms, Part II
R. Heath-Brown
2:00pm|S-101

This is an exposition of work on Artin's Conjecture on the zeros of p-adic forms.A variety of lines of attack are described ,going back to 1945.However there is particular emphasis on recent developments concerning quartic forms on the one hand ,and...

Analytic and Geometric Number Theory Seminar

Oct
22
2009

Analytic and Geometric Number Theory Seminar

Towards Schmidt's Theorem for Algebraic Points of Bounded Degree
2:00pm|S-101

The Schmidt subspace theorem is a deep generalization of Roth's theorem in Diophantine approximation to the setting of hyperplanes in projective space. Another well-known generalization of Roth's theorem is the theorem of Wirsing, which extends Roth...

Oct
29
2009

Analytic and Geometric Number Theory Seminar

Global Divisibility of Heegner points and Tamagawa Numbers
Dimitar Jetchev
2:00pm|S-101

We improve Kolyvagin's upper bound on the order of the p-primary part of the Shafarevich-Tate group of an elliptic curve of rank one over a quadratic imaginary field. In many cases, our bound is precisely the one predicted by the Birch and...

Nov
05
2009

Analytic and Geometric Number Theory Seminar

Prime Chains and Applications
2:00pm|S-101

A sequence of primes $p_1, \dotsc , p_k$ is a prime chain if $p_{j+1} \equiv 1 \pmod{p_j}$ for each $j$. For example: 3, 7, 29, 59. We describe new estimates for counts of prime chains satisfying various properties, e.g. the number of chains with $p...

Nov
19
2009

Analytic and Geometric Number Theory Seminar

Small Gaps Between Primes, and Between Almost Primes
C. Y. Yildirim
2:00pm|S-101

An overview of methods and results concerning small gaps between primes, between almost primes, and the consequences on values taken by certain arithmetical functions will be presented. The material is from the works with Goldston, Graham and Pintz...

Dec
03
2009

Analytic and Geometric Number Theory Seminar

Half-Dimensional Sieve, Multiplicative Functions and Rational Points
2:00pm|S-101

In the first half of the talk I will give details of my joint work with Henryk Iwaniec. We use half-dimensional sieve to obtain a lower bound for the density of rational points on the cubic Chatelet surface. The cubic Chatelet surface can also be...

Dec
10
2009

Analytic and Geometric Number Theory Seminar

The Inverse Conjectures for the Gowers Norms
2:00pm|S-101

For the last 5 years or so Terry Tao and I have been working on a programme to prove certain conjectures of Hardy and Littlewood concerning the number of primes vectors p = (p_1, . . . ,p_n) in some box which satisfy the equation Ap = b . The number...

Jan
21
2010

Analytic and Geometric Number Theory Seminar

The Positive Density Conjecture for Integral Apollonian Packings
Elena Fuchs
2:00pm|S-101

A bounded Apollonian circle packing (ACP) is an ancient Greek construction which is made by repeatedly inscribing circles into the triangular interstices in a Descartes configuration of four mutually tangent circles. Remarkably, if the original four...

Jan
28
2010

Analytic and Geometric Number Theory Seminar

Bounds Toward Ramanujan Over a Number Field
Farrell Brumley
2:00pm|S-101

A result of Kim-Sarnak (2003) gives the best known bounds towards the Ramanujan conjecture for Maass forms. The technique employed has not, until now, been made to apply to general GL2 cusp forms over number fields whose unit group is infinite. In...

Feb
03
2010

Analytic and Geometric Number Theory Seminar

A Subconvexity Bound for automorphic L-Functions for SL(3,Z)
Liangyi Zhao
2:00pm|S-101

In this joint work with Stephan Baier, we prove a subconvexity bound for Godement-Jacquet L-functions associated with Maass forms for SL(3,Z). The bound arrives from extending a method of M. Jutila (with new ingredients and innovations) on...

Feb
04
2010

Analytic and Geometric Number Theory Seminar

On the Sup-Norm of Maass Forms of Large Level
2:00pm|S-101

We discuss the question of quantitative bounds on the sup-norm of automorphic cusp forms. We present an improvement on a recent result by Blomer-Holowinsky on Hecke-Maass forms on $X_0(N)$ with large level $N$. Analogous results are then established...

Feb
11
2010

Analytic and Geometric Number Theory Seminar

Quadratic Polynomials Represented by Norms
2:00pm|S-101

Let K/Q be an extension of number fields. The Hasse norm theorem states that when K is cyclic any non-zero element of Q can be represented as a norm from K globally if and only if it can be represented everywhere locally. In this talk I will discuss...

Feb
25
2010

Analytic and Geometric Number Theory Seminar

Analytic Methods to Compute Dirichlet L-Functions and Character Sums
2:00pm|S-101

I first present an algorithm to compute the truncated theta function in poly-log time. The algorithm is elementary and suited for computer implementation. The algorithm is a consequence of the periodicity of the complex exponential, and the self...

Mar
04
2010

Analytic and Geometric Number Theory Seminar

One Parameter Families of Elliptic Curves with Maximal Galois Representations
A. C. Cojocaru
2:00pm|S-101

Let E be an elliptic curve over Q and let Q(E[n]) be its n-th division field. In 1972, Serre showed that if E is without complex multiplication, then the Galois group of Q(E[n])/Q is as large as possible, that is, GL_2(Z/n Z), for all integers n...

Mar
11
2010

Analytic and Geometric Number Theory Seminar

Distribution of extreme values of L-functions in the strip 1/2 < Re(s) < 1
2:00pm|S-101

In this talk I will construct a class of probabilistic random Euler products to model the behavior of L-functions in the strip 1/2 Re(s) 1. We then deduce results on the distribution of extreme values of several families of L-functions, including...

Mar
25
2010

Analytic and Geometric Number Theory Seminar

Metaplectic Ramanujan Conjecture and Ternary Quadratic Forms Over Function Fields
Jacob Tsimerman
2:00pm|S-101

The Ramanujan conjecture states that for a holomorphic cusp form $f(z) =\sum_{n \in N} \lambda_f(n)e(nz)$ of weight $k$, the coefficients $\lambda_f(n)$ satisfy the bound $|\lambda_f(n)| \ll_\epsilon n^{(k−1)/2+\epsilon}$. In the case where $k$ is...

André Joyal’s 70th Birthday

André Weil -- A Conference on His Work and its Influence

Arithmetic Combinatorics

Sep
25
2007

Arithmetic Combinatorics

Applications of Quadratic Fourier Analysis
Tim Gowers
2:00pm|S-101

An important theme in arithmetic combinatorics, which is closely related to the ergodic-theoretic project of understanding characteristic factors, is higher-order Fourier analysis. It has been well known for a long time that various norms defined in...

Oct
02
2007

Arithmetic Combinatorics

Difference Sets and the Primes
2:00pm|S-101

We shall discuss joint work with I Z Ruzsa in which it is shown that if A is a subset of {1,..,N} such that its difference set contains no number of the form $p-1$ for $p$ a prime, then $|A|=O(N\exp(-c\sqrt{4}{\log N}))$ for some absolute $c>0$.

Oct
09
2007

Arithmetic Combinatorics

On Square Sum-Free Sets
2:00pm|S-101

Let A be subset of {1,...,n}. We say that A is square sum-free if the sum of any two different elements of A is not a square. Erdos and Sarkozy asked whether a square sum-free set can have more than n(1/3+epsilon) elements (motivated by the sequence...

Oct
23
2007

Arithmetic Combinatorics

Polynomial Progressions in Primes
2:00pm|S-101

In 1977 Szemeredi proved that any subset of the integers of positive density contains arbitrarily long arithmetic progression. A couple of years later Furstenberg gave an ergodic theoretic proof for Szemeredi's theorem. At around the same time...

Oct
30
2007

Arithmetic Combinatorics

On the Property Testing of Hereditary Graph and Hypergraph Properties
Terrence Tao
2:00pm|S-101

Recent work of Alon-Shapira and Rodl-Schacht has demonstrated that every hereditary graph and hypergraph property is testable with one-sided error. This result appears definitive, but there are some subtleties to it that I will present here. For...

Nov
06
2007

Arithmetic Combinatorics

The Rank of Symmetric Matrices
Kevin Costello
2:00pm|S-101

Let Q(n,p) denote the adjacency matrix of the Erdos-Renyi graph G(n,p), that is to say a symmetric matrix whose entries above the main diagonal are independently set to 1 with probability p and 0 with probability 1-p. We will examine the behavior of...

Nov
13
2007

Arithmetic Combinatorics

Product Growth and Mixing in Finite Groups: Variations on a Theme of Gowers
László Babai
2:00pm|S-101

For a probability distribution X over a finite set, let D(X) denote the L_2-distance of X from the uniform distribution. Let X, Y be probability distributions over the finite group G and let Z be their G-convolution. Inspired by recent work of...

Nov
14
2007

Arithmetic Combinatorics

Decompositions into Quadratic Phase Functions
2:00pm|S-101

The aim is to present some of the more technical aspects of my joint project with Tim Gowers regarding the true complexity of a system of linear quations. Using so-called "quadratic Fourier analysis", we determined a necessary and sufficient...

Nov
27
2007

Arithmetic Combinatorics

Inverse Theorems for Large Subsets of sums of Dissociated Sets
2:00pm|West Building Lecture Theatre

Let $G$ be a finite Abelian group, say $Z/NZ$. A set $\Lambda = \{ lambda_1, \dots, \lambda_{m} \}$ is called {\it dissociated} if any equality $\sum_{i=1}^m \varepsilon_i \lambda_i = 0$, where $\varepsilon_i \in \{ 0,\pm 1 \}$ implies that all $...

Dec
05
2007

Arithmetic Combinatorics

Some Properties of Sum and Product Sets in Finite Fields
2:30pm|West Building Lecture Theatre

We will study the following problem: Given $n$ subsets $A_1, A_2,\ldots, A_n\subset \mathbb{F}_q$ of a finite field $\mathbb{F}_q$ with $q$ elements. Let $|A_1|\cdot |A_2|\cdot\ldots dot|A_n|>q^{1+\varepsilon}$ for some $\varepsilon>0,$ one needs to...

Arithmetic Combinatorics Mini-Course

Arithmetic Geometry Seminar