## Past Events at the University of British Columbia

### Past Events

- 20-Mar-07

Amenable groups that are left orderable

Let G be an abstract group. It is known that if every finitely generated subgroup of G has an infinite cyclic quotient, then G is left orderable. Using an idea of E.Ghys, we prove that the converse is true for all amenable groups. (This generalize more››

Scientific Event

- 19-Mar-07

Mathematical Models of Protein Receptor Trafficking and Its Role in Synaptic Plasticity

AMPA receptors mediate the majority of fast excitatory synaptic transmission in the central nervous system, and recent experimental evidence suggests that AMPA receptor trafficking regulates synaptic strength, a phenomenon implicated in learning a more››

Scientific Event

- 19-Mar-07

Some arithmetic groups that are not left orderable

It is known that finite-index subgroups of the arithmetic group SL(3,Z) are not left orderable. (In other words, they have no interesting actions on the real line.) This naturally led to the conjecture that most other arithmetic groups (of higher more››

Scientific Event

- 19-Mar-07

Issues with Bayesian Analysis of Inverse Problems

A computer/math model of a process often contains numerous unknown parameters. To utilize the model, these parameters either must be determined from expert knowledge or estimated from data. In the mathematical community, the most common methods of more››

Scientific Event

- 16-Mar-07

Black Hole Physics and Mathematics Through Scientific Computing

I will give an overview of ongoing calculations in numerical relativity at UBC and elsewhere. The talk will include a gentle introduction to Einstein's theory of gravity (general relativity) and the role of black holes in the theory. The nature of more››

Scientific Event

- 15-Mar-07

Intermittent behaviour in hydrodynamical systems with spherical symmetry: theory and an experiment

Auxiliary variable methods for the incompressible Navier-Stokes equations approximate the evolution of the velocity through a dynamic variable which does not satisfy a divergence constraint but from which the correct incompressible velocity can be more››

Scientific Event

- 15-Mar-07

Pricing and Hedging in Illiquid Financial Markets

Ever since the seminal work of Black, Scholes, and Merton, typical models studied in Mathematical Finance specify price dynamics exogenously via some more or less explicit semimartingale dynamics. This is in contrast to the basic economic paradigm more››

Scientific Event

- 15-Mar-07

Characters and Primitive Ideal Spaces of Nilpotent Discrete Groups

If G is a discrete abelian group, then the space of maximal ideals of the L1- and the C*-algebra of G is homeomorphic to the compact dual group of G. This generalizes to some extent to discrete nilpotent groups G, where the the dual gro more››

Scientific Event

- 15-Mar-07

- 13-Mar-07

Mean Curvature Flows For Isoparametric Submanifolds

Isoparametric submanifolds in Euclidean spaces and spheres are submanifolds with constant pincipal curvatures. We will show that the mean curvature flows of such submanifolds behaves very well. They always converge in finite time to smooth submani more››

Scientific Event

- 12-Mar-07

Red points and blue points occur as independent Poisson processes in R^d, and we consider schemes to perfectly match red points to blue points in a translation-invariant way. For any matching scheme in dimensions 1 and 2, the distance X from a typ more››

Scientific Event

- 12-Mar-07

One of the central tenets of signal processing is the Shannon/Nyquist sampling theory: the number of samples needed to reconstruct a signal without error is dictated by its bandwidth-the length of the shortest interval which contains the support o more››

Scientific Event

- 12-Mar-07

Characters of unipotent groups over finite fields

Let G be a connected unipotent group over a finite field F_q. For each natural number n, we have the unique extension F_{q^n} of F_q of degree n, and we can form the finite group G(F_{q^n}) of points of G defined over F_{q^n}. An interesting more››

Scientific Event

- 9-Mar-07

- 8-Mar-07

Risk management for a hydro-based generator

This talk will cover some of the practical applications of risk analysis and hedging programs for a hydro-based energy generator such as BC Hydro. Risk management for BCH provides a unique challenge due to the significant variability in available more››

Scientific Event

- 7-Mar-07

Symmetric Markov chains on Z^d with unbounded range

We consider symmetric Markov chains on ^d where we allow arbitrarily large jumps. Under a uniform second moment condition on the conductances, we look at estimates on the transition probabilities, Harnack inequalities, and CLTs. This is joint wor more››

Scientific Event

- 7-Mar-07

Identifications in Modular Group Algebras

Let G be a finite p-group and F a field of characteristic p>0. In this talk I shall explain how Lie theoretic methods can be used to identify certain subgroups of G inside the augmentation ideal of the group algebra FG. more››

Scientific Event

- 6-Mar-07

- 2-Mar-07

In this paper, directional frames, known as curvelets, are used to recover seismic data and images from noisy and incomplete data. Sparsity and invariance properties of curvelets are exploited to formulate the recovery by a $\ell_1$-norm promoting more››

Scientific Event