Seminars

Mar
08
2016

Computer Science/Discrete Mathematics Seminar II

Fast learning requires good memory: a time-space lower bound for parity learning
10:30am|S-101

We prove that any algorithm for learning parities requires either a memory of quadratic size or an exponential number of samples. This proves a recent conjecture of Steinhardt, Valiant and Wager and shows that for some learning problems a large...

Mar
07
2016

Computer Science/Discrete Mathematics Seminar I

Almost optimal sum of squares lower bound for planted clique
11:15am|S-101

Finding cliques in random graphs and the related planted variant where one wants to recover an added clique of size $k$ added to a random $G(n, 1/2)$ graph, have been extensively studied questions in algorithm design. Despite intense effort, state...

Mar
01
2016

Computer Science/Discrete Mathematics Seminar II

Graph isomorphism in quasipolynomial time II
László Babai
10:30am|S-101

The algorithm indicated in the title builds on Luks's classical framework and introduces new group theoretic and combinatorial tools. In the first talk we outline the algorithm and state the core group theoretic and algorithmic ingredients. Some of...

Feb
29
2016

Computer Science/Discrete Mathematics Seminar I

Graph isomorphism in quasipolynomial time I
László Babai
11:15am|Wolfensohn Hall

The algorithm indicated in the title builds on Luks's classical framework and introduces new group theoretic and combinatorial tools. In the first talk we outline the algorithm and state the core group theoretic and algorithmic ingredients. Some of...

Feb
23
2016

Computer Science/Discrete Mathematics Seminar II

Minkowski sums, mixed faces and combinatorial isoperimetry
Karim Adiprasito
10:30am|S-101

I want to sketch some algebraic and geometric tools to solve a variety of extremal problems surrounding Minkowski sums of polytopes and colorful simplicial depth.

Feb
22
2016

Computer Science/Discrete Mathematics Seminar I

The deterministic communication complexity of approximate fixed point
Omri Weinstein
11:15am|S-101

We study the two-party communication complexity of the geometric problem of finding an approximate Brouwer fixed-point of a composition of two Lipschitz functions $g \circ f$, where Alice knows $f$ and Bob knows $g$. We prove an essentially tight...

Feb
16
2016

Computer Science/Discrete Mathematics Seminar II

The singularity of symbolic matrices
10:30am|S-101

While this lecture is a continuation of the lecture from last Tuesday, I will make it self contained. The main object of study of this talk are matrices whose entries are linear forms in a set of formal variables (over some field). The main problem...

Feb
09
2016

Computer Science/Discrete Mathematics Seminar II

The singularity of symbolic matrices
10:30am|S-101

The main object of study of this talk are matrices whose entries are linear forms in a set of formal variables (over some field). The main problem is determining if a given such matrix is invertible or singular (over the appropriate field of...

Feb
08
2016

Computer Science/Discrete Mathematics Seminar I

Bipartite perfect matching is in quasi-NC
Stephen Fenner
11:15am|S-101

We show that the bipartite perfect matching problem is in $\textrm{quasi-}\textsf{NC}^2$. That is, it has uniform circuits of quasi-polynomial size and $O(\log^2 n)$ depth. Previously, only an exponential upper bound was known on the size of such...

Feb
02
2016

Computer Science/Discrete Mathematics Seminar II

Constant-round interactive-proofs for delegating computations (continued)
Ron Rothblum
10:30am|S-101

We will continue Monday's talk on constant-round interactive proofs, going into more details of the full construction and its proof. We will also briefly recap Monday's talk so that it will be beneficial to those who cannot attend on Monday.