2019-2020 Seminars

Oct
28
2019

Computer Science/Discrete Mathematics Seminar I

Furstenberg sets in finite fields
11:00am|Simonyi Hall 101

A (k,m)-Furstenberg set K in F^n, where F is a finite field, is a set such that any k-dimensional subspace of F^n can be shifted so that it intersects K in at least m points. Such sets generalize in a natural way finite field Kakeya sets (in which k...

Oct
23
2019

Theoretical Machine Learning Seminar

Optimization Landscape and Two-Layer Neural Networks
12:00pm|Dilworth Room

Modern machine learning often optimizes a nonconvex objective using simple algorithm such as gradient descent. One way of explaining the success of such simple algorithms is by analyzing the optimization landscape and show that all local minima are...

Oct
22
2019

Computer Science/Discrete Mathematics Seminar I

Towards a theory of non-commutative optimization: geodesic 1st and 2nd order methods for moment maps and polytopes
Rafael Oliveira
10:30am|Simonyi Hall 101

Scaling problems, such as operator scaling and tensor scaling, have recently found several applications in diverse areas of math and CS. They have been used to give efficient algorithms for non-commutative rational identity testing, compute the...

Oct
21
2019

Computer Science/Discrete Mathematics Seminar I

Learning arithmetic circuits in the average case via lower bounds
Ankit Garg
11:00am|Simonyi Hall 101

The problem of learning arithmetic circuits is the following: given a polynomial as a black box that is promised to have a small arithmetic circuit computing it, can we find this arithmetic circuit? This problem is hard in the worst case and so...

Oct
15
2019

Computer Science/Discrete Mathematics Seminar I

Asymptotic spectra and Applications II
10:30am|Simonyi Hall 101
In this second lecture in my series on asymptotic spectra we will focus on one application: the matrix multiplication problem. We will use the asymptotic spectrum of tensors to prove that a very general method (that includes the methods used to...
Oct
14
2019

Computer Science/Discrete Mathematics Seminar I

Choiceless Polynomial Time
Ben Rossman
11:00am|Simonyi Hall 101

The choiceless computation model of Blass, Gurevich and Shelah (1999, 2002) is an algorithmic framework for computing isomorphism-invariant properties of unordered structures. Machines in this model have the power of parallel execution, but lack the...

Oct
09
2019

Theoretical Machine Learning Seminar

Designing Fast and Robust Learning Algorithms
12:00pm|Dilworth Room

Most people interact with machine learning systems on a daily basis. Such interactions often happen in strategic environments where people have incentives to manipulate the learning algorithms. As machine learning plays a more prominent role in our...

Oct
08
2019

Theoretical Machine Learning Seminar

Unsupervised Ensemble Learning
12:00pm|White-Levy

In various applications, one is given the advice or predictions of several classifiers of unknown reliability, over multiple questions or queries. This scenario is different from standard supervised learning where classifier accuracy can be assessed...

Oct
08
2019

Computer Science/Discrete Mathematics Seminar I

Asymptotic spectra and Applications I
10:30am|Simonyi Hall 101
The first lecture in this series is an introduction to the theory of asymptotic spectra. This theory describes asymptotic behavior of basic objects in mathematics like graphs and tensors. Example applications that we will see are the matrix...