2006 Scientific Events

  • 18-Dec-06

Volume, twist number, and the Jones polynomial of hyperbolic knots

I will describe a few results that relate combinatorial data about a knot or link projection to geometric and topological information about the link complement. For a large family of knots and links, one single piece of diagrammatic data (the twis   more››

University of British Columbia

  • 12-Dec-06

Self-avoiding walk enumeration via the lace expansion

We introduce a new method for the enumeration of self-avoiding walks based on the lace expansion combined with another algorithmic improvement which we call the two step method. We have been able to significantly extend series for the simple cubic   more››

University of British Columbia

  • 12-Dec-06

Drift diffusion equations with fractional diffusion and the quasi-geostrophic equation

The critical dissipative quasi-geostrophic equation was proposed by several authors as a toy model to study the regularity of solutions to 3D Navier-Stokes equations. In this work, in collaboration with L. Caffarelli, we prove that drift-diffusion   more››

University of British Columbia

  • 7-Dec-06

Time-Frequency Analysis: From Wireless Communications to Abstract Harmonic Analysis

In the talk I will discuss the relation between problems in wireless communications and time-frequency analysis. I will explain the basic principle of OFDM (orthogonal frequency division multiplexing) and its formulation in time-frequency analysis   more››

University of Calgary

  • 6-Dec-06

PIMS Probability Seminar 2006

If we would -say- estimate the anthropogenic contribution to climate change, we would have to understand the range of natural variability. Now, the climate of the Earth is an experiment, which is only run once, so in order to assess this we have t   more››

University of Alberta

  • 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

Mathematical models in radiation biology

In this talk, I will review concepts in radiation biology that allow us to model the effectiveness of radiation therapy in the treatment of cancer. In particular, I will focus on the Tumour Control Probability (TCP), which is the probability that   more››

University of British Columbia

  • 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

  • 22-Nov-06

A Geometric Proof of the Blakers-Massey Theorem

In this talk we give a geometric proof of the Blakers-Massey Theorem using Mather's Cube Theorems. As an application, we use this result to compute the James Splitting of Omega S^n.   more››

University of British Columbia

  • 21-Nov-06

Multi-level Micro-Finite Element Analysis for Human Bone Structures

Using microarchitectural bone imaging, it is possible to assess both the apparent density and the trabecular microstructure of intact bones in a single measurement. In combination with microstructural finite element (microFE) analysis this could p   more››

University of British Columbia

  • 21-Nov-06

Generic subsets of Thompson's group

Richard Thompson constructed an example of a group which is called 'F'that has many unusual properties. One way to consider its elements is in terms of pairs of rooted binary trees. This viewpoint lends itself nicely to counting subsets of el   more››

University of British Columbia

  • 20-Nov-06

Modeling relapse in infectious diseases

An integro-differential equation is proposed to model a general relapse phenomenon in infectious diseases including herpes. The basic reproduction number Ro for the model is identified and a threshold property of Ro established. For the case of a   more››

University of British Columbia

  • 20-Nov-06

Feasible Proofs and Computations

The concepts of proof and computation are central to virtually any intellectual human activity. However, before the remarkable advances of the 20th century mathematical logic, the border between them had never been sharp even in the context of pur   more››

Simon Fraser University

  • 20-Nov-06

Feature Selection through Lasso: model selection consistency and the BLasso algorithm

Information technology advances are making data collection possible in most if not all fields of science and engineering and beyond. Statistics as a scientific discipline is challenged and enriched by the new opportunities resulted from these high   more››

University of Washington

  • 17-Nov-06

Random 0/1 polytopes

University of Calgary

  • 16-Nov-06
  • 16-Nov-06

A Galois correspondence for reductive groups and applications to the First Fundamental Theorems

Following some unpublished ideas of Lex Schrijver we will explain a new approach to the First Fundamental Theorems (FFTs) from classical invariant theory. It uses the tensor product of the two tensor algebras $T(V)$ and $T(V^*)$ with the aim to se   more››

University of British Columbia

  • 16-Nov-06

SL(2,C) Character Varieties of 3-Manifold Groups

In continuation of the intro from last time, I will give an overview of some applications of SL(2,C) character varieties to 3-manifold topology. We will then discuss possible topics for the following seminars and will assign speakers.   more››

University of British Columbia

  • 15-Nov-06

Random walk in random environment on a strip

I am going to define the model, discuss briefly an interesting particular case of it, and present some limit theorems recently obtained for RWRE on strips. I am going to build my talk around the comparison of this model to the well-studied RWRE on   more››

University of British Columbia

  • 15-Nov-06

Finite subset spaces of the circle and a theorem of Bott

By considering the circle as the boundary of the hyperbolic plane we are able to describe the first three unordered configuration spaces of the circle by considering them as particular quotients of the group of isometries of the hyperbolic plane.   more››

University of British Columbia

  • 14-Nov-06

Galloping instability of viscous shock waves

This is joint work with Kevin Zumbrun (Indiana University). Motivated by physical and numerical observations of time oscillatory galloping, spinning, and cellular instabilities of detonation waves, we study Poincare--Hopf bifurcation of traveling-   more››

University of British Columbia

  • 10-Nov-06

Glacier and ice sheet dynamics

Glaciers and ice sheets are thin viscous gravity currents subject to mass sources and sinks due to surface snow accumulation and melting. Mathematically, the evolution of glacier geometry poses interesting free boundary problems. Land-based glaciers   more››

Simon Fraser University

  • 9-Nov-06

Dynamic Asset Allocation: a Portfolio Decomposition Formula and Applications

This paper establishes a new decomposition of the optimal portfolio policy in dynamic asset allocation models with arbitrary vNM preferences and Ito prices. The formula rests on a change of num'{e}raire which consists in taking pure discount bonds   more››

University of British Columbia

  • 9-Nov-06

A stochastic two-state signalling module with negative feedback

Motivated by the negative feedback calcium exerts on the gating dynamics of a calcium-conducting ion channel in olfactory receptor neurons, we develop an abstract two-state (open/closed) signalling module with negative feedback. The coupling betwe   more››

University of British Columbia

  • 7-Nov-06
  • 7-Nov-06

Perfect Matchings under Vertex Deletion

University of British Columbia

  • 6-Nov-06

Modelling individual to collective cell movement

Kevin Painter is with Heriot-Watt University, Edinburgh, Scotland Abstract: Cell migration plays a major role in both embryonic development (e.g. gastrulation, neural crest migration) and the normal physiological responses of an adult (e.g.   more››

University of Alberta

  • 6-Nov-06

A History of the Trace Formula

The trace formula is a far reaching generalization of the Poisson summation formula. It relates spectral data of deep arithmetic significance to explicit but complicated geometric data. With its applications to the Langlands programme, some alread   more››

University of Toronto

  • 6-Nov-06

Hedging Under Jump Diffusion with Transaction Costs

In this talk, we consider the problem of hedging a contingent claim, where the underlying asset follows a jump diffusion process. The no-arbitrage value of the claim is given by the solution of a Partial Integro-Differential Equation (PIDE), which   more››

University of British Columbia

  • 3-Nov-06

Optimal Drug Therapy for Chronic Myelogenous Leukemia

Drug therapy is introduced as a control in a mathematical model for chronic myelogenous leukemia (CML). The cancer is modeled as a system of ODE's representing the dynamics between the immune systen in the body and cancer cells. We introduce two cont   more››

Simon Fraser University

  • 3-Nov-06

A Polymer Model Explains MinDE Dynamics in E. coli Cell Division

In Escherichia coli, the location of the site for cell division is regulated by the action of the Min proteins. These proteins undergo a periodic pole-to-pole oscillation that involves polymerization and ATPase activity of MinD under the controlling   more››

Simon Fraser University

  • 3-Nov-06

Canonical metrics and collapsing manifolds

University of British Columbia

  • 2-Nov-06

Heights of polynomials and random matrix theory

We will discuss a method for producing asymptotic estimates for the number of integer polynomials of degree N with bounded (but large) Mahler's measure. This method also produces a closed form for averages of class functions over ensembles of asym   more››

University of British Columbia

  • 2-Nov-06

The Diophantine equation aX4-bY2=1

In a series of papers over nearly forty years, Ljunggren derived remarkably sharp bounds for the number of solutions to various quartic Diophantine equations, particularly those of the shape aX4-bY2=±1, typically via a sophisticated application o   more››

University of British Columbia

  • 1-Nov-06

Invasion percolation on regular trees

We consider invasion percolation on a rooted regular tree. For the infinite cluster invaded from the root, we identify the scaling behaviour of its connectivity functions, and of its volume both at a given height and below a given height. We find   more››

University of British Columbia

  • 1-Nov-06

Some self-interacting random walks

We will discuss two different classes of self-interacting random walks. Firstly, in joint work with Akira Sakai, we consider a simple model of a random walk with reinforcement but with very short term spatial memory. The simplicity of these 'Senil   more››

University of British Columbia

  • 25-Oct-06
  • 25-Oct-06
  • 24-Oct-06

Some mathematical challenges in nuclear medical imaging problems

We give a brief description of some of the challenging problems in medical imaging, particularly those related to nuclear medicine. We will describe some recent progress made in dual-isotope SPECT image reconstruction - obtaining two images from a   more››

University of British Columbia

  • 24-Oct-06

Gaussian processes, kinematic formulae and Poincare's limit

The main aim of this talk will be to prove the specific result that the mean invariant measures of the excursion sets f^{-1}(D) of the vector-valued isotropic Gaussian process f on the n-sphere have a specific form, highly reminiscent of the Kinem   more››

University of British Columbia

  • 23-Oct-06

New geometric and functional analytic ideas arising from problems in symplectic geometry

The study of moduli spaces of holomorphic curves in symplectic geometry is the key ingredient for the construction of symplectic invariants. These moduli spaces are suitable compactifications of solution spaces of a first order nonlinear Cauchy-Ri   more››

University of British Columbia

  • 23-Oct-06

The quantum McKay correspondence in dimension two

Let G be a finite subgroup of SU(2). The classical McKay correspondence describes the cohomology ring of Y the minimal resolution of C2/G in terms of the representation theory of G. We give a description of the quantum cohomology of Y in terms of   more››

University of British Columbia

  • 23-Oct-06

Wild fish, farmed fish and sea lice—a big-box model with spatial effects

The Anderson-May dynamical model for host-macroparasite systems is extended to include resource limitation and the distribution of both resource limitation effects and parasite pathogenicity over host mortality and natality. When the equilibrium h   more››

University of British Columbia

  • 20-Oct-06

Going with the (Information) Flow: on efficient computations & boundary value problems.

The direction of information propagation can be used to de-couple certain systems of nonlinear equations. This fundamental principle is the basis of Dijkstra's classical method for finding shortest paths on graphs. We will use the continuous analogue   more››

Simon Fraser University

  • 19-Oct-06

Fluid Mathematical Models of Traffic Flow

I will start with a few basic facts on other types of description (microscopic, kinetic ...) Then I will talk about fluid models, of 'first order': Lighthill-Whitham-Richards (LWR) , i.e. a scalar conservation law, robust and (too ?) simple. The f   more››

University of British Columbia

  • 19-Oct-06

Impact of Travel Between Patches for Spatial Spread of Disease

A patch model is proposed to study the impact of travel on the spatial spread of disease between patches. The basic reproduction number for the i-th patch in isolation, is obtained along with the basic reproduction number of the system, $mathcal{R   more››

University of British Columbia

  • 18-Oct-06

Arithmetic Fuchsian groups of genus two

A hyperbolic 2- or 3-orbifold M is called arithmetic if M = H^2/G or H^3/G where G is an arithmetic Fuchsian or Kleinian group, respectively. Considerable work has been done in the last two decades classifying these groups. I will explain how arit   more››

University of British Columbia

  • 16-Oct-06

Frozen boundaries and log-fronts

In this talk, based on a joint work with Richard Kenyon and Grisha Mikhalkin, Andrei Okounkov will discuss some simple binary operation on plane curves which 1) generalizes classical duality for plane curves, 2) arises naturally in probabilistic c   more››

University of British Columbia

  • 16-Oct-06

Epizootics of wild fish induced by farm fish

The continuing decline of ocean fisheries and rise of global fish consumption has driven aquaculture growth by 10% annually over the last decade. The association of fish farms with disease emergence in sympatric wild fish stocks remains one of the   more››

University of Alberta

  • 16-Oct-06

Integral cohomology of singular toric varieties

The singular cohomology and Chow cohomology, with Q-coefficients, of projective toric varieties with at worst orbifold singularities are well-understood, but interesting problems remain for toric varieties with more serious singularities and for c   more››

University of British Columbia

  • 13-Oct-06

Applied Math Show and Tell

The first annual applied math show and tell will be an opportunity graduate students and other faculty to learn about what faculty in the applied math group are doing. Each speaker will have under five minutes to give a one paragraph intro to their r   more››

Simon Fraser University

  • 12-Oct-06

Implicit Immersed Boundary Methods with Boundary Mass

The immersed boundary method is a general framework used to handle fluid-structure interactions. One computational bottleneck of the immersed boundary methods is that the elastic structures are often very stiff, necessitating the use of a very fin   more››

University of British Columbia

  • 12-Oct-06
  • 23-Oct-06

Northwest Probability Seminar

Northwest Probability Seminars are one-day mini-conferences held at the University of Washington and organized in collaboration with the Oregon State University, the University of Brit   more››

University of Washington

  • 12-Oct-06
  • 16-Oct-06

Frontiers in Biophysics: Modelling and Experiment.

Frontiers in Biophysics: Modelling and Experiment is a weekend retreat that is being organized by graduate students and faculty in biophysics and mathematical biology at Simon Fraser University and the University of British Columbia. This event is   more››

University of British Columbia

  • 11-Oct-06

Effect of noise on front propagation in KPP equations

We study random traveling waves in KPP equations with appropriate additive noise. We prove a very explicit conjecture of Brunet and Derrida concerning the dramatic slowdown of these fronts by the noise. This is joint work with Carl Mueller and Leo   more››

University of British Columbia

  • 11-Oct-06

Aspects of Khovanov homology

Khovanov's construction of a homology theory for knots allows us to view the Jones polynomial as an Euler characteristic, provides a stronger knot invariant, and is the main tool for Rasmussen's combinatorial proof of the Milnor conjecture. In thi   more››

University of British Columbia

  • 11-Oct-06

The 290-Theorem and Representing Numbers by Quadratic Forms

This talk will describe several finiteness theorems for quadratic forms, and progress on the question: "Which positive definite integer-valued quadratic forms represent all positive integers?". The answer to this question depends on sett   more››

University of British Columbia

  • 10-Oct-06

Three challenges of Claude Shannon

In 1948/1949 Claude Shannon wrote two papers~[Sha48,Sha49] which became the foundation of modern information theory. The papers showed that information can be compressed up to the `entropy', that data can be transmitted error free at a rate below   more››

University of British Columbia

  • 10-Oct-06

Common Agency with Informed Principals: an Economics Lecture

The provision of public goods under asymmetric information has generally been viewed as a mechanism design problem under the aegis of an uninformed mediator. This paper focuses on institutional contexts where no such mediator is available. Contrib   more››

University of British Columbia

  • 10-Oct-06

Regularity criteria for Navier-Stokes equations

In the talk I will first review various known regularity criteria and partial regularity theory for 3D incompressible Navier-Stokes equations. I will then talk about a joint work with Gustafson and Kang on regularity criteria based on scaled space   more››

University of British Columbia

  • 6-Oct-06

Formal proofs in geometry

Traditional mathematical proofs are written in a way to make them easily understood by mathematicians. Routine logical steps are omitted. An enormous amount of context is assumed on the part of the reader. Proofs, especially in topology and geomet   more››

University of Calgary

  • 6-Oct-06

Three-dimensional Turing patterns: Stability, implications in biological modeling, and equilibrium

Turing patterns are structures that can form spontaneously in systems of reacting and diffusing chemicals. Since the 1950s, when Alain Turing first put forth the theoretical considerations, there has been a vast amount of literature on the subject. I   more››

Simon Fraser University

  • 5-Oct-06

Functional equations for Mahler measures of genus-one curves

The Mahler measure of an n -variable polynomial P is the integral of log | P | over the n -dimensional unit torus T n with the Haar measure. Consider a family of two-variable polynomials whose coefficients depend on one parameter. Then the Mahler mea   more››

University of British Columbia

  • 4-Oct-06

Computer-assisted proofs in geometry

In recent years, computer-assisted proofs have become relatively common. For example, in 2002, W. Tucker published a proof of problem 14 (concerning strange attractors) on Smale's list of problems for the new century. Other recent computer-assiste   more››

University of Calgary

  • 3-Oct-06

Semilinear elliptic systems with exponential nonlinearities in two dimensions

We study the existence of nontrivial solutions for the following system of two coupled semilinear Poisson equations: left{ begin{array}{rlllllll} -Delta u &=& g(v), & v & > & 0 & extrm{in} Ω, \ -Delta v &=&   more››

University of British Columbia

  • 3-Oct-06

Exponential integrators

Numerical schemes for ordinary differential equations, using matrix exponentials, were introduced in the 1960's as a way to overcome the stability restrictions of explicit methods. However, such methods were not considered as a practical mean of s   more››

University of British Columbia

  • 2-Oct-06

Overview of a Methodology for Developing and Assessing Simulation Models of Complex Systems

in computer hardware, recent reviews have concluded that such models have generally not fulfilled their potential for advancing ecological understanding. This state of affairs is at least partially the result of little attention being given   more››

University of Alberta

  • 2-Oct-06

Sphere Packings and foams

Kepler's conjecture asserts that the densest possible arrangement of congruent balls in three dimensions is the familiar pyramid arrangement, which is used to stack oranges at the fruit stand. A 300-page proof of this theorem finally appeared in J   more››

University of Calgary

  • 2-Oct-06

Ehrhart analogue of the h-polynomial

In this talk I will explain how the Ehrhart problem of counting lattice points in a polyhedron is equivalent to a problem in orbifold cohomology. This equivalence can be used to prove a conjecture of Stanley that relates the Ehrhart generating pol   more››

University of British Columbia

  • 30-Sep-06
  • 1-Oct-06

Pacific Northwest Numerical Analysis Seminar

The Twentieth Annual Pacific Northwest Numerical Analysis Seminar will be hosted by the Department of Mathematics at Simon Fraser University. The meeting will run from   more››

Simon Fraser University

  • 28-Sep-06

Perturbations Methods in Default Modeling

Stochastic volatility has played a central role in modeling equity derivative markets. In the recent years the market in credit-linked derivative products has grown tremendously and had generated a need for more sophisticated models of default. We   more››

University of British Columbia

  • 28-Sep-06

The integral geometry of random sets

In various scientific fields from astro- and high energy physics to neuroimaging, researchers observe entire images or functions rather than single observations. The integral geometric properties, notably the Euler characteristic of the level/excu   more››

University of Calgary

  • 27-Sep-06
  • 30-Sep-06

Bridging the scales of disease dynamics 2006

The ongoing HIV pandemic, the brief SARS epidemic of 2003 and recurrent fears of a serious influenza outbreak have raised public consciousness of issues surrounding the behaviour and evolution of infectious diseases as they spread through a p   more››

University of British Columbia

  • 27-Sep-06
  • 28-Sep-06

Probability of hitting a far point for the voter model

We consider a voter model on the integer lattice started with a single one at the origin. In dimensions 2 and 3, we establish the precise asymptotic behaviour of the probability for the voter model to hit a distant point. We use the scaling limit   more››

University of British Columbia

  • 25-Sep-06

Primitivity in twisted homogeneous coordinate rings

Given a projective k-scheme X, an automorphism sigma of X and an invertible sheaf L on X, one can form the twisted homogeneous coordinate ring bigoplus_{nge 0} H0(X,L_n), where L_n=Lotimes L^{sigma}otimes cdotsotimes L^{sigma^{n-1}. We study the q   more››

University of British Columbia

  • 21-Sep-06

Mathematical Analysis of the Neural Control of Hormone Secretion

The pituitary is one of the primary glands of the body. Many hormones are released from a variety of cells within the pituitary, and these hormones regulate the release of hormones from other glands and have direct actions on the brain, muscles, a   more››

University of British Columbia

  • 19-Sep-06

Comparing sumsets and difference sets

Since addition is commutative but subtraction is not, the subset S+S of a finite set S is predisposed to be smaller than the difference set S-S. As Mel Nathanson wrote: Even though there exist sets S that have more sums than differen   more››

University of British Columbia

  • 18-Sep-06

A Mirror Theorem for Complete Intersection Orbifolds in Weighted Projective Spaces

The famous mirror formula for quintic threefolds, conjectured to Candelas, de la Ossa, Green, and Parkes, provides detail information on genus zero Gromov-Witten invariants of the quintic threefold. Mirror formula has been extended to larger class   more››

University of British Columbia

  • 18-Sep-06

Prediction of dispersal and establishment of aquatic nonindigenous species across Ontario lakes: Linking vector-based and habita

Prediction of range expansion of nonindigenous species is important, as it is often easier to prevent invasions than to mitigate impacts once invasions have occurred. A combination of models for propagule pressure (gravity models) and habitat matc   more››

University of Alberta

  • 14-Sep-06

Closed form solution for maximizing CRRA type utility

This paper studies the problem of optimal investment in incomplete markets when the agents have CRRA type utility. Closed form solutions are obtained up to some unhedgeble risk represented by a process orthogonal on the stock price. The   more››

University of British Columbia

  • 14-Sep-06

On classifications of links up to C_n-moves

A C_n-move (nin{Bbb N}) is a local move on links defined by Habiro, which can be regarded as a 'higher order crossing change'. The C_n-equivalence is an equivalence relation on links generated by C_n-move. The C_m-equivalence implies the C_n-equiv   more››

University of British Columbia

  • 14-Sep-06
  • 14-Sep-06

Nucleation of localised pattern in continuous media

The formation of patterns from quiescence under the continuous variation of a parameter has long been of interest across the physical and life sciences since the pioneering work of Alan Turing. We describe how spatially localised patches of patter   more››

University of British Columbia

  • 13-Sep-06

The loop-erased random walk and the uniform spanning tree on the four-dimensional discrete torus

Let x and y be points chosen uniformly at random from the four-dimensional discrete torus with side length n. We show that the length of the loop-erased random walk from x to y is of order n2 (log n)^{1/6}, resolving a conjecture of Benjamini and   more››

University of British Columbia

  • 13-Sep-06

Ionic and Metabolic Mechanisms in Pulsatile Insulin Secretion

Insulin is secreted in pulses with a period of about 5 minutes from the beta-cells of the pancreas. These pulses are in turn driven by oscillations of cytosolic calcium. Two parallel streams of investigation over more than two decades have studied   more››

University of British Columbia

  • 13-Sep-06

Subfactors and (1+1)-dimensional TQFTs (Part 2)

University of British Columbia

  • 12-Sep-06

Subfactors and (1+1)-dimensional TQFTs (Part 1)

In this joint work with Vijay Kodiyalam (IMSc, Chennai) and Vishwambhar Pati (ISI, Bangalore), we construct a certain 'cobordism category' D whose morphisms are suitably decorated cobordism classes between similarly decorated closed oriented 1-man   more››

University of British Columbia

  • 11-Sep-06

Linearly reductive finite group schemes

I will report on joint work with Dan Abramovich and Martin Olsson. We classify linearly reductive finite group schemes in positive or mixed characteristic, and use this to define a good replacement for the notion of orbifold in positive or mixed c   more››

University of British Columbia

  • 11-Sep-06

Spatiotemporal patterns in models of biological invasion and epidemic spread

This seminar is intended to give an informal overview of my previous work and some recent ideas. I am especially interested in patterns of spatiotemporal dynamics that are induced by the joint interplay of spatial spread, demographics (e.g., Allee   more››

University of Alberta

  • 6-Sep-06

System Level Mathematical Analysis of Mitosis

Mitotic spindle goes through distinct morphological states characterized by increasing spindle length and distances between chromosomes. A complete picture of how the spindle assembles is still lacking. We performed an In Silico model screen to id   more››

University of British Columbia

  • 6-Sep-06
  • 9-Sep-06

Stability and instability of nonlinear waves

Stability plays an essential role in many branches of science and engineering, including several aspects of fluid mechanics, high-speed transmission of information, and feasibility of MHD fusion devices. The objective of the workshop is to g   more››

University of Washington

  • 5-Sep-06

Prime numbers, Riemann, and Langlands

Prime numbers have held a mystery over number theory since before Euclid. To introduce a powerful new tool to the subject, Riemann defined his analytic zeta function; with it, he described the Prime Number Theorem and conjectured Riemann's Hypothe   more››

University of British Columbia

  • 30-Aug-06

Geometric flow in Kahler manifold

We will discuss some recent results on the Calabi flow, short time existence, stability and extension theorem. The Calabi flow is a 4th order parabolic flow which is gradient flow of certain convex functional in infinite dimensional space. If we h   more››

University of British Columbia

  • 22-Aug-06

Characterizing projective spaces

University of British Columbia

  • 14-Aug-06
  • 16-Aug-06

18th Canadian Conference on Computational Geometry

The Canadian Conference on Computational Geometry (CCCG) focuses on the mathematics of discrete geometry from a computational point of view. Abstracting and studying the geometry problems that underlie important applications of computing (   more››

Queen's University

  • 14-Aug-06
  • 18-Aug-06

Geophysical Inversion Workshop

The second PIMS GIW will be held on the University of Calgary Campus in August of 2006. Like the first event (2003), the purpose is to bring together mathematicians and geophysicists to focus on a challenging inver   more››

University of Calgary

  • 14-Aug-06
  • 19-Aug-06

Canadian Quantum Information Students' Conference

The Canadian Quantum Information Students' Conference (CQISC) offers the ideal environment for graduate students interested in all areas of Quantum Information Theory and Experiment to meet an collaborate. Students of computer science, mathem   more››

University of Calgary

  • 9-Aug-06

CECM Summer Meeting 2006

CECM, Maplesoft, MITACS, IRMACS and PIMS are pleased to present "CECM 2006", a summer conference hosted by CECM under the title "Summer Workshop on Computational Mathematics" at Simon Fraser University. The Workshop   more››

Simon Fraser University

  • 7-Aug-06
  • 11-Aug-06

International Conference on Stochastic Analysis and its Applications

The main topics of the conference will be: Stochastic analysis and its applications Markov processes, including jump type processes and measure-valued processes Dirichlet forms Analysis on fractals and percolation clusters These areas are strong   more››

University of Washington

  • 7-Aug-06
  • 12-Aug-06

Sixth Canadian Summer School on Quantum Information Processing

The goal of this summer school is to introduce a general audience of computer scientists, physicists, and mathematicians with little or no background in quantum information processing to this exciting and growing field. Quantum information pro   more››

University of Calgary

  • 7-Aug-06
  • 19-Aug-06

Summer School on Strings, Gravity and Cosmology

This will be the fourth in an ongoing series of annual summer schools in theoretical physics held in Canada. The first and second editions of these schools were held at the University of British Columbia. The third summer school took place at the Per   more››

University of Alberta

  • 18-Jul-06

Heisenberg-Weyl groups and their application to sequence design

We will describe how Heisenberg-Weyl groups appear in the construction of phase coded radar waveforms, in the design of spreading sequences in wireless communications, and in the theory of classical and quantum error-correcting codes. Interesti   more››

Simon Fraser University

  • 18-Jul-06

Question and Answer Session

A rare event for students (undergraduate and graduate) to meet two of the most acclaimed mathematical scientists of our time. PIMS invites you to attend a special informal question & answer session with these speakers after their lectures, to be   more››

Simon Fraser University

  • 18-Jul-06

Introduction to Wavelets

Wavelets are a new approach used in the analysis of sounds and images, as well as in many other applications. The wavelet transform provides a mathematical analog to a music score: just as the score tells a musician which notes to play whe   more››

Simon Fraser University

  • 17-Jul-06
  • 22-Jul-06

Sequences and Codes

The conference will explore new research directions within the fields of sequence design and algebraic error-correcting codes, including radar applications of sequence design, algebraic constructions of space-time   more››

Simon Fraser University

  • 12-Jul-06

Some arithmetic problems raised by rabbits, cows and the Da Vinci Code

In 1202, the Italian mathematician Leonardo da Pisa, alias Fibonacci, introduced a sequence of numbers that nowadays bears his name. Under the assumption that rabbits breed (producing a pair of rabbits) when   more››

Simon Fraser University

  • 12-Jul-06
  • 11-Jul-06

The Physics of Eternity

The Physics of Eternity Recent evidence points to an open universe, where time might run forever. If we take the current laws of physics, and run things forward, what could we see of the far future? We find some predictions out to 10**15 years are fa   more››

Simon Fraser University

  • 10-Jul-06
  • 21-Jul-06

Summer School on Frontiers in Mathematics and Economics

The summer school brings together graduate students, postdoctoral fellows and young faculty members from business schools, economics, mathematics and operations research with leading economists and mathematicians. It exposes students in business a   more››

University of British Columbia

  • 7-Jul-06

Polynomials, Permutations, Prime Ideals, and factoring Polynomials modulo p

The talk began as an attempt to answer the following question - if f(x) is an irreducible polynomial with integer coefficients, does it remain irreducible modulo p for infinitely many primes p? It turns out that the answer is sometimes yes and som   more››

Simon Fraser University

  • 27-Jun-06

On the Untraced Second Bianchi Identities in General Relativity

Einstein's equations set space-time curvature traces proportional to the space-time's mechanical content expressed as a stress- energy tensor. The divergence of a stress-energy tensor is the external force density acting on the matter described by th   more››

Simon Fraser University

  • 23-Jun-06
  • 25-Jun-06

Western Canada Linear Algebra Meeting (WCLAM)

The 2006 Western Canada Linear Algebra Meeting (WCLAM) will be held at the University of Victoria in room C112 of the David Strong Building on June 23-24, 2006. This is the seventh in a series of meetings that have been held since 1993; the p   more››

University of Victoria

  • 22-Jun-06

Modelling homotopy n-types in algebraic topology and category theory

Homotopy n-types are topological spaces with trivial homotopy groups in dimension greater than n. They arise naturally in algebraic topology and category theory. Both these areas of mathematics have seen the development of models of n-types. In th   more››

University of British Columbia

  • 21-Jun-06

DIGITAL SNOWFLAKES

Several mathematical models of snow crystal growth will be discussed. For a popular class of cellular automata known as Packard's Snowflakes, one can develop a fairly complete rigorous theory, addressing limiting density, fractal shapes and   more››

University of British Columbia

  • 13-Jun-06

Relativistic Wave equations in Discrete phase space

A new representation of quantum mechanics involving finite difference operators will be presented. Relativistic lattice Klein-Gordon equation, Dirac equation, and Maxwell's equations as partial difference equations will be discussed. It is proved tha   more››

Simon Fraser University

  • 10-Jun-06
  • 20-Jun-06

2006 Summer School on Mathematical Modeling of Infectious Diseases

The purpose of this summer school is to provide effective training for collaborative research in infectious diseases based on mathematical modeling and qualitative analysis. The school is designed for epidemiology and public health graduate students,   more››

York Univerisity

  • 6-Jun-06

Quantification of Blow-up Levels for a 2-D Elliptic Equation with Critical Exponential Nonlinearity

We study sequences of solutions of some elliptic PDE’s, on 2-dimensional bounded domain, with critical Moser-Trudinger exponential nonlinearity. We prove that lack of compactness occur only when standard bubbles appear and thus we can quantify t   more››

University of British Columbia

  • 5-Jun-06

Stochastic PDEs for Sampling Conditioned SDEs

Stochastic PDEs for Sampling Conditioned SDEs   more››

Simon Fraser University

  • 5-Jun-06

Large Inverse Problems and Infinite Dimensional Sampling: Stochastic PDE for Sampling Conditioned SD

There are a variety of important applications which may be formulated as inverse problems where the object of interest is the time-dependent solution of a dynamical system. Examples include the sampling of rare events in molecular dynamics, data assi   more››

Simon Fraser University

  • 5-Jun-06
  • 13-Jun-06

Motives and Periods

The conference is intended to cover recent developments in the study of motives and periods with an emphasis to the connections to physics, arithmetic and algebraic cycles. The conference has an instructional component which consists of a series   more››

University of British Columbia

  • 31-May-06

Probability Seminar 2006

On the existence of cut points for Brownian motion on fractals   more››

University of British Columbia

  • 29-May-06
  • 3-Jun-06

Canadian Operator Symposium 2006

The 34-th Annual Canadian Operator Symposium (COSy) will take place at the University of Calgary campus from May 29th to June 2, 2006. The meeting will be an occasion to celebrate the 65-th birthday of   more››

University of Calgary

  • 25-May-06

Data Driven Algorithm Design

Bernard Chazelle (born November 5, 1955) is a professor of computer science at Princeton University. Although he is best known for his invention of the soft heap data structure and the most asymptotically efficient known algorithm for finding mini   more››

Simon Fraser University

  • 24-May-06

Quantum Information Theory for Mathematicians

In this talk I will give an overview of quantum information theory, with an emphasis on some of the underlying mathematics. In particular, quantum algorithms depend on a physical property of quantum systems,entanglement, which may be characterized   more››

University of British Columbia

  • 24-May-06

MITACS Math Biology Seminar 2006

Rolling is an important manifestation of biological cell adhesion, especially for the leukocyte cell in the immune process. It combines several phenomena such as the affinity, the junction and failure between specific adhesion molecules, and an ac   more››

University of British Columbia

  • 18-May-06
  • 22-May-06

Fifth International Conference on Scientific Computing and Applications

This will be the fifth of a sequence of conferences on Scientific Computing and Applications held in the Pacific Rim region. All of them have the goal of bringing together mathematicians, scientists and engineers working in the field of scie   more››

University of Alberta

  • 5-May-06

Algebraic Topology Seminar 2006

We study the concepts of homotopy disjointness and homotopy disjointness by small deformation for mappings between spheres. Joint work with Daciberg Goncalves produced the following result. The existence of a mapping f: S^(4n-2)   more››

University of British Columbia

  • 3-May-06

Probability Seminar 2006

The first part of the talk gives a survey about BSDE. Linear BSDE have been introduced by Bismuth (1973) in Control Theory. The existence of solutions for Lipschitz BSDE was proven by Peng, and for quadratic BSDE by Lepeltier/San Martin and by Kob   more››

University of British Columbia

  • 1-May-06

Algebraic Geometry Seminar 2006

Mixed Hodge structures on the cohomology of theta divisors     more››

University of British Columbia

  • 26-Apr-06

Renormalization analysis of hierarchically interacting two-type branching models

Linearly interacting diffusions model the evolution of colonies of populations. When the interaction kernel is of an appropriate form and the diffusions are indexed by the hierarchical group, the large scale space-time behavior of the system exhib   more››

University of British Columbia

  • 26-Apr-06

MITACS Math Biology Seminar 2006

A fundamental attribute of living cells is their ability to move. I will talk about two forms of biological motion driven by different physical mechanisms. The polymerization of the protein, actin, appears to be the source of the propulsive force   more››

University of British Columbia

  • 24-Apr-06
  • 25-Apr-06

Algebraic Geometry Seminar 2006

Title: On the motive of a Shimura variety Speaker: Arvind Nair (Tata Institute for Fundamental Research, Mumbai, Maharashtra, India) Date and Time: Monday, April 24 2006, 01:30 PM - 02:30 PM Location: West Mall Annex Room 11   more››

University of British Columbia

  • 21-Apr-06
  • 22-Apr-06
  • 20-Apr-06

Wavelet techniques for processing multifractal signals

Multifractal analysis has been successfully applied to many types of signals, starting from turbulence velocity fields, and then extending to traffic, economic and medecine signals. In each case, it supplies new parameters which allow for a fine c   more››

University of British Columbia

  • 20-Apr-06

PIMS/SFU Computing Science DISTINGUISHED LECTURE SERIES 2006

How to draw a Graph?   more››

Simon Fraser University

  • 19-Apr-06

Bootstrap Percolation in d Dimensions

Modified bootstrap percolation is a very simple cellular automaton model for nucleation and growth. Sites in the cube {1,...,L}^d are initially occupied independently with probability p. At subsequent steps, an unoccupied site becomes occupied if   more››

University of British Columbia

  • 12-Apr-06

Probability Seminar 2006

Edge Reinforced Random Walk: How long till attracting edge?   more››

University of British Columbia

  • 12-Apr-06

Polarisation and cell movement: a multiscale modelling approach

Cell motility is a complex phenomenon, in which the cytoskeleton and its major constituent, actin, play an essential role. To understand the intricated interplay which brings about cell motility, we use a multiscale modelling approach in a 2D model o   more››

University of British Columbia

  • 11-Apr-06

Channel Assignments in Infinite Graph

We study quaternionic (especially hyperkahler) analogues of Lerman's symplectic cut construction. In low dimensions this can be physically interpreted as adding a brane to a hyperkahler manifold   more››

University of British Columbia

  • 10-Apr-06

Algebraic Geometry Seminar 2006

Adding branes to hyperkahler manifolds   more››

University of British Columbia

  • 8-Apr-06
  • 10-Apr-06

ABC Algebra Workshop

Speaker: Skip Garibaldi Title: Cohomological invariants Abstract: The most familiar example of a cohomological invariant is the discriminant of a separable field extension or of a quadratic form. The subject of this   more››

University of British Columbia

  • 6-Apr-06

A talk by Melanie West (Co-founder of Tiz Media Foundation and Originator of MindRap)

MindRap uses an innovative learning process that involves technology, music, art, performing, writing, collaboration, culture, self-esteem, and mentoring. High school students learn how to create animated multimedia modules that include their own art   more››

University of British Columbia

  • 6-Apr-06

Climate Risk, Securitization, and Equilibrium Bond Pricing

We propose a method of pricing financial securities written on non-tradable underlyings such as temperature or precipitation levels. To this end, we analyze a financial market where agents are exposed to financial and non-financial risk factors. The   more››

University of British Columbia

  • 6-Apr-06

Some applications of the graph of supersingular elliptic curves over a finite field

The graph of supersingular elliptic curves over a finite field connected by isogenies has many applications in computational number theory. In this talk we look at some old (in number theory) and new (in cryptography) applications of these gr   more››

Simon Fraser University

  • 5-Apr-06

Pathwise uniqueness for parabolic stochastic pde's

Consider the SPDE: du/dt=u''+g(u)dW/dtdx where dW/dtdx is space-time white noise and g is Holder continuous of index h. It is shown that if 2h^3-h > 3/4 then pathwise uniqueness holds. The proof is an infinite dimensional extension of the Yamada-W   more››

University of British Columbia

  • 5-Apr-06

Commuting Elements in Lie Groups

In this talk we discuss the topology and geometry of the space of pairs of commuting elements in a Lie group. We will see part of the work of Adem and Cohen on SU(2) as well as some recent advances in the case of U(2).   more››

University of British Columbia

  • 5-Apr-06

A Reward Model for Mate Choice and Sexual Selection

Females are the choosy sex, their choice being made on the basis of the quality of the males. The benefits they receive from the males for the offspring are either indirect, for example good genes, or direct, such as territories, male parental care a   more››

University of British Columbia

  • 4-Apr-06

Activation Analysis in Functional Magnetic Resonance Brain Imaging with Applications in Parkinsons Disease

This talk will present some of our recent work on spatial characterization of activation patterns in functional magnetic resonance imaging (fMRI) of the brain. Exploiting techniques for region of interest (ROI) characterization and statistical a   more››

Simon Fraser University

  • 1-Apr-06
  • 3-Apr-06

Third Annual Young Researchers Conference for Mathematical and Statistical Sciences

On behalf of the University of Alberta, the Department of Mathematical and Statistical Sciences invited the mathematical graduate student community to the 2006 Young Researchers Conference for Mathematical and Statistical Sciences.   more››

University of Alberta

  • 1-Apr-06
  • 3-Apr-06

Pacific Northwest Geometry Seminar

Alejandro Adem (University of British Columbia) A Stringy Product for Twisted Orbifold K-theory Given an orbifold X with inertia orbifold LX, we construct a product for the twisted K-theory of LX which extends the orbifol   more››

University of British Columbia