2021-2022 Seminars

Nov
09
2021

Computer Science/Discrete Mathematics Seminar II

Introduction to Continuous Combinatorics II: semantic limits
10:30am|Simonyi Hall 101 and Remote Access

The field of continuous combinatorics studies large (dense) combinatorial structures by encoding them in a "continuous" limit object, which is amenable to tools from analysis, topology, measure theory, etc. While the syntactic/algebraic approach of...

Nov
08
2021

Computer Science/Discrete Mathematics Seminar I

The Kakeya Set conjecture over Z mod N for general N
Manik Dhar
11:15am|Simonyi Hall 101 and Remote Access

A Kakeya Set in (Z/N Z)^n is a set that contains a line in every direction.  It has been known for over a decade that such sets must be large when N is prime (or more generally over any finite field).  This goes back to Dvir's proof of the finite...

Nov
02
2021

Computer Science/Discrete Mathematics Seminar II

Introduction to Continuous Combinatorics I: the semidefinite method of flag algebras
10:30am|Wolfensohn Hall and Remote Access

The field of continuous combinatorics studies large (dense) combinatorial structures by encoding them in a "continuous" limit object, which is amenable to tools from analysis, topology, measure theory, etc. The syntactic/algebraic approach of "flag...

Nov
01
2021

Computer Science/Discrete Mathematics Seminar I

Parallel Repetition for the GHZ Game: A Simpler Proof
Uma Girish
11:15am|Wolfensohn Hall and Remote Access

We give a new proof of the fact that the parallel repetition of the (3-player) GHZ game reduces the value of the game to zero polynomially quickly.  That is, we show that the value of the n-fold parallel repetition of the GHZ game is at most n^{-...

Oct
26
2021

Computer Science/Discrete Mathematics Seminar II

Locally testable codes with constant rate, distance, and locality, Part II
10:30am|Simonyi Hall 101 and Remote Access

A locally testable code (LTC) is an error correcting code that admits a very efficient membership test. The tester reads a constant number of (randomly - but not necessarily uniformly - chosen) bits from a given word and rejects words with...

Oct
25
2021

Computer Science/Discrete Mathematics Seminar I

Locally testable codes with constant rate, distance, and locality, Part I
11:15am|Simonyi Hall 101 and Remote Access

A locally testable code (LTC) is an error correcting code that admits a very efficient membership test. The tester reads a constant number of (randomly - but not necessarily uniformly - chosen) bits from a given word and rejects words with...

Oct
19
2021

Computer Science/Discrete Mathematics Seminar II

An Introduction to Determinantal Point Processes
10:30am|Simonyi Hall 101 and Remote Access

A random point process is said to be determinantal if finite subset probabilities correspond to principal minors of some matrix. Determinantal point processes (DPPs) appear in a wide variety of settings, from random matrix theory to combinatorics...

Oct
18
2021

Computer Science/Discrete Mathematics Seminar I

Sharp matrix concentration inequalities
Ramon van Handel
11:15am|Simonyi Hall 101 and Remote Access

What does the spectrum of a random matrix look like when we make no assumption whatsoever about the covariance pattern of its entries?  It may appear hopeless that anything useful can be said at this level of generality. Nonetheless, a widely used...

Oct
12
2021

Computer Science/Discrete Mathematics Seminar II

Recent progress in query complexity I & II
10:30am|Simonyi Hall 101 and Remote Access

The query model is one of the most basic computational models.  In contrast to the Turing machine model, fundamental questions regarding the power of randomness and quantum computing are relatively well-understood.  For example, it is well-known...