2007-2008 seminars

Oct
01
2007

Computer Science/Discrete Mathematics Seminar I

The Pattern Matrix Method for Lower Bounds on Quantum Communication
Alexander Sherstov
11:15am|S-101

In a breakthrough result, Razborov (2003) gave optimal lower bounds on the communication complexity of every function f of the form f(x,y)=D(|x AND y|) for some D:{0,1,...,n}->{0,1}, in the bounded-error quantum model with and without prior...

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...

Sep
25
2007

Computer Science/Discrete Mathematics Seminar II

Hardness of Solving Sparse Overdetermined Linear Systems
10:30am|S-101

Solving a system of linear equations is a fundamental algorithmic task arising in numerous applications. It is possible to tell in polynomial time, by Gaussian elimination, if a given system admits a solution, and if so to find one. But what if the...

Sep
24
2007

Computer Science/Discrete Mathematics Seminar I

Towards Universal Semantic Communiction
Madhu Sudan
11:15am|S-101

Is it possible for two intelligent players to communicate meaningfully with each other, without any prior common background? What does it even mean for the two players to understand each other? In addition to being an intriguing question in its own...

Sep
17
2007

Computer Science/Discrete Mathematics Seminar I

Algebrization: A New Barrier in Complexity Theory
11:15am|S-101

Any proof of P!=NP will have to overcome two barriers: relativization and natural proofs. Yet over the last decade, we have seen circuit lower bounds (for example, that PP does not have linear-size circuits) that overcome both barriers...