Past Events

Cayley graphs provide interesting bridges between graph theory, additive combinatorics and group theory. Fixing an ambient finite group, random Cayley graphs are constructed by choosing a generating set at random.

​​​​An ascent sequence is a sequence a1a2 · · · an consisting of non-negative integers satisfying a1 = 0 and for 1 < i ≤ n, ai ≤ asc(a1a2 ·

We develop and analyze a general technique for learning with unknown distribution drift. Given a sequence of independent observations from the last T steps of a distribution that evolves over

A poset is short for a partially ordered set. The most common example of a poset is the power set of $[n]$ with the partial relation given by inclusion. Given

Consider a gambler who starts with x dollars. At each gamble, the gambler either wins a dollar with probability 1/2 or loses a dollar with probability 1/2. The gambler's goal

Approximating the action of a matrix function f(A) on a vector b is an increasingly important primitive in machine learning, data science, and statistics, with applications such as sampling high

Everyone knows (hopefully) Ramsey's Theorem that 2-colorings of infinite graphs contain monochromatic subsets. In this talk, we investigate generalizations of this fact to general linear orders. We first discuss operations

In combinatorics, we happily manipulate formal power series, taking no heed of whether they might converge. Applied mathematicians encounter series with no radius of convergence, about which they worry. Jean

In this talk, I will give our recent result on the problem of assigning items to agents so as to maximize the emph{weighted} Nash Social Welfare (NSW) under submodular valuations.

A linear extension of P is a linear ordering compatible with the poset relations. Let p(x

Is this number irrational? This question has been troubling mathematicians since the time of Pythagoras, and inspired a search for good rational approximations of constants. Examining the literature on irrationality,

A function that maps n-bit strings to N-bit strings is called an isometric embedding of the n-dimensional Hamming metric space to the N-dimensional edit metric space if the Hamming distance

Erdős unit distance problem asks the following: Let $P$ be a set of $n$ distinct points in the plane, and let $U(P)$ denote the number of pairs of points in

We will walk through several combinatorial results. Half of them have important motivation coming from computer science and the other half explain surprising observations made by experimentation. We will begin

In the directed Steiner tree problem, we are given an edge-weightedgraph G, a root r, and a set of terminals K. The goal is to find a minimum-cost subgraph of

** Please note day change to Tuesday Many problems in discrete geometry can be naturally encoded by a graph. Using tools from graph theory then gives information about the original

Over a period of 20 years, Eric Angelini contributed 1700 brilliant, clever, witty sequences to the OEIS. I will discuss seven of them: "Which terms are primes?", The Jungfrau, Solar

I will present results on the exact and asymptotic enumeration of corner polyhedra, a special class of simple orthogonal polyhedra introduced by Eppstein and Mumford, whose enumeration can be considered

We show that every fractionally k-edge-connected weighted graph (i.e. every solution to the canonical k-edge-connectivity linear program) can be rounded to an integral (k-10)-edge-connected graph of no greater cost. This

In a landmark paper in 1992, Stanley developed the foundations of what is now known as the Kazhdan--Lusztig--Stanley (KLS) theory. To each kernel in a graded poset, he associates special