Previous Conferences & Workshops

Dec
11
2017

Theoretical Machine Learning Seminar

Learning with little data
12:30pm|White-Levy Room

The current successes of deep neural networks have largely come on classification problems, based on datasets containing hundreds of examples from each category. Humans can easily learn new words or classes of visual objects from very few examples...

Dec
11
2017

Computer Science/Discrete Mathematics Seminar I

Recent advances in high dimensional robust statistics
Daniel Kane
11:00am|S-101

It is classically understood how to learn the parameters of a Gaussian even in high dimensions from independent samples. However, estimators like the sample mean are very fragile to noise. In particular, a single corrupted sample can arbitrarily...

Dec
08
2017

Mathematical Conversations

Proofs from algorithms, algorithms from proofs
6:00pm|Dilworth Room

Constructive vs Pure Existence proofs have been a topic of intense debate in foundations of mathematics. Constructive proofs are nice as they demonstrate the existence of a mathematical object by describing an algorithm for building it. In computer...

Dec
08
2017

Special Seminar

Integral points and curves on moduli of local systems
Junho Peter Whang
5:05pm|S-101

The classical affine cubic surface of Markoff has a well-known interpretation as a moduli space for local systems on the once-punctured torus. We show that the analogous moduli spaces for general topological surfaces form a rich family of log Calabi...

Dec
08
2017

Special Seminar

An asymptotic for the growth of Markoff-Hurwitz tuples
Ryan Ronan
4:15pm|S-101

For integer parameters $n \geq 3$, $a \geq 1$, and $k \geq 0$ the Markoff-Hurwitz equation is the diophantine equation \[ x_1^2 + x_2^2 + \cdots + x_n^2 = ax_1x_2 \cdots x_n + k.\] In this talk, we establish an asymptotic count for the number of...

Dec
08
2017

Special Seminar

Integral points on Markoff-type cubic surfaces
3:00pm|S-101

We report on some recent work with Peter Sarnak. For integers $k$, we consider the affine cubic surfaces $V_k$ given by $M(x) = x_1^2 + x_2 + x_3^2 − x_1 x_2 x_3 = k$. Then for almost all $k$, the Hasse Principle holds, namely that $V_k(Z)$ is non...

Dec
08
2017

Special Seminar

Markoff surfaces and strong approximation
2:10pm|S-101

Markoff triples are integer solutions of the equation $x^2+y^2+z^2 = 3xyz$ which arose in Markoff's spectacular and fundamental work (1879) on diophantine approximation and has been henceforth ubiquitous in a tremendous variety of different fields...

Dec
08
2017

Special Seminar

Diophantine analysis in thin orbits
1:15pm|S-101

We will explain how the circle method can be used in the setting of thin orbits, by sketching the proof (joint with Bourgain) of the asymptotic local-global principle for Apollonian circle packings. We will mention extensions of this method due to...

Dec
07
2017

Joint IAS/Princeton University Number Theory Seminar

From counting Markoff triples to Apollonian packings; a path via elliptic K3 surfaces and their ample cones
Arthur Baragar
4:30pm|Fine 214, Princeton University

The number of integer Markoff triples below a given bound has a nice asymptotic formula with an exponent of growth of 2. The exponent of growth for the Markoff-Hurwitz equations, on the other hand, is in general not an integer. Certain elliptic K3...