Computer Science and Discrete Mathematics (CSDM)

The Unique-Games Conjecture is a central open problem in the field of PCP’s (Probabilistically Checkable Proofs) and hardness of approximation, implying tight inapproximability results for wide class of optimization problems.

We will discuss PCPs...

Let X be the infinite graph partially pictured below, the "free product graph" C_4 * C_4 * C_4. Let FinQuo(X) be the set of all finite graphs G that covered by X (i.e., that 'locally resemble' X; i.e., that consist of C_4's joined 3-to-a-vertex). A...

For a family of graphs F, a graph G is F-universal if G contains every graph in F as a (not necessarily induced) subgraph. A natural candidate to serve as universal graph G is the random graph G(n,p). In this case, we want to find an optimal p for...

A graph G is called a small set expander if any small set of vertices contains only a small fraction of the edges adjacent to it. This talk is mainly concerned with the investigation of small set expansion on the Grassmann Graphs, a study that was...

Edit distance is a widely used measure of similarity of two strings based on the minimum number of character insertions, deletions, and substitutions required to transform one string into the other. The edit distance can be computed exactly using a...

These two talks will introduce the asymptotic rank and asymptotic subrank of tensors and graphs - notions that are key to understanding basic questions in several fields including algebraic complexity theory, information theory and combinatorics.

M...

We will describe a recently discovered connection between private information retrieval and secret sharing, and a new secret-sharing scheme for general access structures that breaks a long-conjectured exponential barrier.

Based on joint work with...

These two talks will introduce the asymptotic rank and asymptotic subrank of tensors and graphs - notions that are key to understanding basic questions in several fields including algebraic complexity theory, information theory and combinatorics.

M...

Tensors occur throughout mathematics. Their rank, defined in analogy with matrix rank, is however much more poorly understood, both from a structural and algorithmic viewpoints.

This will be an introductory talk to some of the basic issues...

In their seminal paper, Bennett, Bernstein, Brassard and Vazirani [SICOMP, 1997] showed that relative to an oracle, quantum algorithms are unable to solve NP-complete problems in sub-exponential time (i.e., that Grover's search is optimal in this...