Scientific Lectures

  • 6-Dec-06

Introduction to Brownian snakes

Discrete models for an evolving population -such as branching random walks- arise in a variety of different contexts. In such models, individuals undergo both a branching phenomenon and a spatial displacement. Superprocesses are obtained as the we   more››

University of British Columbia

  • 6-Dec-06
  • 5-Dec-06

New constructions of volume-critical submanifolds of the sphere

Constant mean curvature hypersurfaces in S^n are critical points of the (n-1)-volume functional subject to an enclosed-volume constraint whereas contact-stationary Legendrian (CSL) submanifolds of S^{2n+1} are n-dimensional submanifolds tangent to   more››

University of British Columbia

  • 5-Dec-06

Remarks on split graphs and related notions

A graph is split if its vertices can be covered by two sets A and B where A induces a complete graph and B induces an empty graph. This concept has many related notions. For example, the number of non-isomorphic set covers of a set of order n is t   more››

University of British Columbia

  • 5-Dec-06

An alternative formulation for a delayed logistic equation

After a brief review of the history and dynamics of the classical logistic and delayed logistic equation models, an alternative expression for a delayed logistic equation is derived assuming that the rate of change of the population depends on thr   more››

University of British Columbia

  • 4-Dec-06

Random Sorting Networks

See http://www.math.ubc.ca/~holroyd/sort for pictures. Joint work with Omer Angel, Dan Romik and Balint Virag. Sorting a list of items is perhaps the most celebrated problem in computer science. If one must do this by s   more››

University of British Columbia

  • 4-Dec-06

Plagued by numbers: the mathematics of disease

The dynamics of disease have long fascinated mathematical researchers. From influenza to the bubonic plague, mathematical and computational models are used to evaluate factors governing disease outbreaks. Facts about a disease are put into models.   more››

University of British Columbia

  • 1-Dec-06

High dimensional convex bodies: phenomena, intuitions and results

Phenomena in large dimensions appear in a number of fields of mathematics and related fields of science, dealing with functions of infinitely growing number of variables and with objects that are determined by infinitely growing number of paramete   more››

University of British Columbia

  • 1-Dec-06

Potential energy minimization

Energy minimization can be thought of as a broad generalization of sphere packing. Yudin discovered that harmonic analysis can be applied to prove lower bounds for potential energy. This talk will explain these bounds and show how to use them to p   more››

University of Calgary

  • 30-Nov-06

The action on a tree associated to an ideal point of the character variety

Let G be the fundamental group of a compact, orientable, irreducible 3-manifold M. I will discuss the correspondence between ideal points of a curve in the character variety X(G) and actions of G on a tree (following Culler-Shalen). This is a part   more››

University of British Columbia

  • 30-Nov-06

Optimality of the Leech lattice

This talk will outline the proof that the Leech lattice is the unique densest lattice in R24. The proof combines linear programming bounds with special algebraic and geometric arguments. This is joint work with Abhinav Kumar.   more››

University of Calgary

  • 29-Nov-06

Homotopical group theory I: p-compact groups

University of British Columbia

  • 29-Nov-06

Sphere packing and harmonic analysis

Harmonic analysis is one of the fundamental tools in sphere packing, in the form of "linear programming bounds". This talk will give a survey of linear programming bounds and their applications, as well as a brief introduction to semidef   more››

University of Calgary

  • 29-Nov-06

Hydrodynamic limits of spatially structured coalescents

We are motivated by a question arising in population genetics, and try to describe the effect of migratory fluxes and spatial structure on the genealogy of a population. This leads to the study of systems particles performing simple random walk on   more››

University of British Columbia

  • 28-Nov-06

L^2 decay estimates for oscillatory integral operators in several variables with homogeneous polynomial phases

Oscillatory integral operators mapping $L^2(mathbb R^{n_1})$ to $L^2(mathbb R^{n_2})$ play an important role in many problems in harmonic analysis and partial differential equations. We will briefly discuss the applicability of these operators in   more››

University of British Columbia

  • 28-Nov-06

Puzzles, Tableaux, and Mosaics

The Littlewood-Richardson numbers show up in a number of different areas of mathematics. They are structure constants of the ring of symmetric functions, which connects them to representation theory and cohomology of Grassmannians. There are now s   more››

University of British Columbia

  • 27-Nov-06

The Rotor-router model and Diaconis-Fulton Addition

Given two sets A and B in the lattice, the Diaconis-Fulton sum is a random set obtained by putting one particle in every point of the symmetric difference, and two particles in every point of the intersection, of A and B. Each 'extra particle' per   more››

University of British Columbia

  • 27-Nov-06

Computation of plurigenera of a canonical threefold

For a canonical threefold, there are few known results about plurigenera. We know that a sufficient multiple of canonical divisor generates a nontrivial linear system and that there is a universal multiple. In this talk, we are going to introduce   more››

University of British Columbia

  • 27-Nov-06

For making genetic networks operate robustly, unintelligent non-design suffices

Five years ago we (George von Dassow, Ed Munro, Eli Meir, and Garrett Odell) made mathematical/computer models of two ancient and famous genetic networks that act early in diverse embryos to establish spatial gene expression patterns prefiguring t   more››

University of British Columbia

  • 24-Nov-06

Micro Fluid Mechanics: Some Interface Dynamics Problems

Interface dynamics is of considerable importance in multiphase microfluidic devices such as microheat pipes, and in dewetting dynamics. We consider a liquid meniscus inside a wedge of included angle [pic] that wets the solid walls with a contact a   more››

University of British Columbia