Simon Fraser University

Solvers for the Boolean satisfiability problem have been increasingly used to solve hard problems from many fields and now routinely solve problems with millions of variables. Combinatorial problems are a natural target, as SAT solvers contain...

We explore graphs of high cop number. We give new lower bounds for cop number of graphs of high girth. We also present a new class of undirected graphs with cop number $(1-o(1)) \sqrt{n/2}$ and a class of directed graphs with cop number $(1-o(1))...

A theme that cuts across many domains of computer science and mathematics is to find simple representations of complex mathematical objects such as graphs, functions, or distributions on data. These representations need to capture how the object...

We consider an aggregation model that consists of an active transport equation for the macroscopic population density, where the velocity has a nonlocal functional dependence on the density, modelled via an interaction potential. We set up the model...

We will disucss some recent advances in the convergence of Anderson acceleration, an extrapolation technique that can be applied to general fixed-point iterations. The theory will be illustrated on some examples of systems arising from finite element...

Low Mach number equation sets approximate the equations of motion of a compressible fluid by filtering out the sound waves, which allows the system to evolve on the advective rather than the acoustic time scale. Depending on the degree of...

We consider the Dirichlet problem for a strongly-coupled nonlocal system of equations motivated by peridynamics, a model in continuum mechanics. The strain energy densities involve the magnitude of projected "directional" difference quotients of the...

A double occurrence word w is a word (sequence of letters) in which each of its letters occurs exactly twice. Legal 2-coloring of w is a colouring of individual letters such that each letter occurs once red and once blue. Our goal is to find for a...

Multiplayer games model the behavior of competing agents, and we are interested in the structure that emerges when the number of agents is large. The Dyson and Coulomb games are N-agent dynamic games that admit well studied models of statistical...

In this talk I will introduce a new semi-algebraic proof system, called Stabbing Planes that is in the style of DPLL-based modern SAT solvers. Stabbing Planes proofs extend the DPLL branching from single variables to branching on arbitrary linear...