Previous Conferences & Workshops

Nov
10
2020

SL2 Seminar

Blocks and Defect Groups of SLn
3:00pm|Remote Access

The modular representation theory of a finite group naturally breaks into different pieces called blocks, and the defect of a block is a sort of measure of its complexity. I will recall some basic aspects of this theory, and then give the complete...

Nov
10
2020

Computer Science/Discrete Mathematics Seminar II

Modular zeros in the character table of the symmetric group
10:30am|Remote Access Only - see link below

Miller computed the character table of $S_n$ for some fairly large n's and noticed that almost all of the entries were even. Based on this, he conjectured that the proportion of even entries in the character table of $S_n$ tends to $1$ as $n\to...

Nov
09
2020

Analysis Seminar

Transverse Measures and Best Lipschitz and Least Gradient Maps
4:30pm|Simonyi Hall 101 and Remote Access

Motivated by some work of Thurston on defining a Teichmuller theory based on best Lipschitz maps between surfaces, we study infinity-harmonic maps from a manifold to a circle. The best Lipschitz constant is taken on on a geodesic lamination...

Nov
09
2020

Members’ Seminar

Some analogies between arithmetic and topology
2:00pm|Simonyi Hall 101 and Remote Access

There are striking analogies between topology and arithmetic algebraic geometry, which studies the behavior of solutions to polynomial equations in arithmetic rings. One expression of these analogies is through the theory of etale cohomology, which...

Nov
09
2020

Computer Science/Discrete Mathematics Seminar I

Associativity testing
Ben Green
11:15am|Simonyi Hall 101 and Remote Access - see Zoom link below

Suppose we have a cancellative binary associative operation * on a finite set X. We say that it is delta-associative if the proportion of triples x, y, z such that x*(y*z) = (x*y)*z is at least delta.

Gowers and Long studied somewhat associative...

Nov
06
2020

Workshop on Topology: Identifying Order in Complex Systems

Algebraic and topological models for DNA recombination
Nataša Jonoska
2:00pm|Remote Access Only

DNA rearrangement is observed at developmental and evolutionary scale. The recombination process can be directly modeled by 4-regular graphs and Gauss codes, also called double occurrence words. We discuss properties of these graphs, their spatial...

Nov
05
2020

Joint IAS/Princeton University Number Theory Seminar

Strong approximation for the Markoff equation via nonabelian level structures on elliptic curves
William Chen
4:30pm|Remote Access

Following Bourgain, Gamburd, and Sarnak, we say that the Markoff equation $x^2 + y^2 + z^2 - 3xyz = 0$ satisfies strong approximation at a prime $p$ if its integral points surject onto its $F_p$ points. In 2016, Bourgain, Gamburd, and Sarnak were...

Nov
04
2020

Mathematical Conversations

Three-term arithmetic progressions in sets of integers
Olof Sisask
5:30pm|Remote Access

It turns out that certain additive patterns in the integers are very hard to get rid of. An instance of this is captured in a conjecture of Erdős, which states that as long as a set of natural numbers is 'somewhat dense' -- namely the sum of the...