Past Events

A classical exercise in algebra asks to prove that the product of the pairwise differences between any given n + 1 integers is divisible by the product of the pairwise

The snake graph construction from Musiker-Schiffler-Williams provides an expansion formula for cluster variables in cluster algebras from surfaces. We generalize this construction to generalized cluster algebras from orbifolds. This talk

Observations sampled at different frequencies provide multi-level details. How to effectively use them remains a challenging task. We can aggregate all the data to the lowest-frequency level, or we can

We define a Fibonacci walk to be any sequence of positive integers satisfying the recurrence w_{k+2} = w_{k+2} = w_{k+1}+w_k, and we say that a sequence is an n-Fibonacci walk

This workshop covers the paper-writing process from germ idea to publication, including a 10 step program to get a paper out the door even in the face of many competing

We study the identity y(x)=xA(y(x)), from the theory of rooted trees, proving a conjecture of Greg Kuperberg made in 1996.

Theq-binomial coefficient(nk)q(or the Gaussian binomial coefficient) is a polynomial inq, whereqis a prime power. It can be described combinatorially in several ways. For example, it counts thenumber ofk-dimensional subspaces ofFnqoverFq.

Many important models in phylogenetics can be viewed as toric varieties after a linear change of coordinates. This allows us to use combinatorial techniques to analyze these phylogenetic models. In

Important update The event has been postponed to avoid spread of COVID 19 It will be rescheduled for a future date Nokia Bell Labs will host the Spring 2020 DIMACS Mixer in association with its Shannon Luminary Lecture Series featuring a presentation by Manuela Veloso who will be presented the

Hermite and Serret in 1848 independently devised an algorithm by which to find the two squares which add up to a given prime p of the form 4x+1. It works

Consider the following abstract coin tossing problem: Given a set of n coins with unknown biases, find the most biased coin using a minimal number of coin tosses. This is

The ErdÅ‘s Rényi random graph (denoted Gn,p) is a random object on n vertices where each edge appears independently with probability p. We call a graph rigid if it has

To a sequence associate a permutation $pi$, via: $pi(k)$ is the index of the k-th smallest element of the sequence. This association was introduced in 1987 by Alavi, Malde, Schwenk

Let ρ be a permutation pattern and let S be a set of permutations. A permutation in S is ρ-optimal if it contains at least as many copies of ρ

Numerous problems in computer science and combinatorics can be formulated as searching for objects lacking certain bad properties, or "flaws". For example, constraint satisfaction problems like satisfiability can be seen

Can a rectangle be tiled by finitely-many squares of distinct side lengths, which are almost-disjoint (intersect only at the boundary)? It turns out that this recreational math problem of squaring

Given a graph G, two subsets A and B of its vertex set are a "pure pair" if either all or none of the edges between them are present in

Not all irrational numbers are born equal. The irrationality measure of a number tells you how \`irrational' it is. It is a competitive sport to find better and better bounds

In 2010, Patrascu proposed the Multiphase problem, as a candidate for proving polynomial lower bounds on the operational time of dynamic data structures. Patrascu conjectured that any data structure for

To answer the question in the title, we will develop a systematic method for calculating these numbers using the adjacency matrices of certain directed graphs whose vertices are the conjugacy