## Past Events at the University of British Columbia

### Past Events

- 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››

Scientific Event

- 3-Oct-06

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››

Scientific Event

- 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››

Scientific Event

- 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››

Scientific Event

- 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››

Scientific Event

- 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››

Scientific Event

- 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››

Scientific Event

- 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››

Scientific Event

- 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››

Scientific Event

- 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››

Scientific Event

- 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››

Scientific Event

- 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››

Scientific Event

- 14-Sep-06

Arthur Sherman (Laboratory of Biological Modeling, NIDDK/NIH)

Scientific Event

- 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››

Scientific Event

- 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››

Scientific Event

- 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››

Scientific Event

- 13-Sep-06

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

Scientific Event

- 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››

Scientific Event

- 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››

Scientific Event

- 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››

Scientific Event