Past Events

The quadratic assignment problem, QAP, has many applications ranging from the planning of building locations of a university, to the positioning of modules on a computer chip (VLSI design), to the design of keyboards. This problem is arguably one of...

A video of this event is available on mathtube.org. The (1d) KPZ universality class contains random growth models, directed random polymers, stochastic Hamilton-Jacobi equations (e.g. the eponymous Kardar-Parisi-Zhang equation). It is characterized...

The Dobrushin-Lanford-Ruelle theorem gives sufficient conditions on sets of configurations on the d-dimensional lattice so that (1) every measure which maximizes the topological pressure is a Gibbs measure and (2) every Gibbs measure maximizes the...

A traditional population-genetics approach studies geneaologies in a population of a fixed size, which forms the basis of several spectral theories of finite samples. In contrast, a population of tumor cells typically experiences an exponential...

The main goal of this talk is to introduce transitionally commutative principal G-bundles and to show that they can be classified homotopically using a space B_comG that is called the classifying space for commutativity in G. In the second half of...

This is joint work with Jeffrey Dawson, Linyuan Lu and Attila Sali. We define simple matrices as those whose entries are chosen from {0,1,2} and for which no columns are repeated. We consider the extremal problem of how many columns can an m-rowed...

The relationship between independence number, chromatic number, clique number, clique cover number and their fractional analogues is well-established for perfect graphs. Here, we study the clique k-cover number cck(G) and the fractional clique k...

A video of this event is available on mathtube.org Azumaya algebras over a commutative ring R are generalizations of central simple algebras over a field k, and both are "twisted matrix algebras". In this, they bear the same relationship to a...

For the local time L_t^x of super-Brownian motion X starting from \delta_0, we study its asymptotic behavior as x\to 0. In d=3, we find a normalization \psi(x)=((2\pi^2)^{-1} \log (1/|x|))^{1/2} such that (L_t^x-(2\pi|x|)^{-1})/\psi(x) converges in...

During early vertebrate embryogenesis, neural crest cells (NCCs) migrate in clusters from the neural tube to various target locations over long distances. Their collective migration is tightly regulated by environmental signals and intercellular...