Scientific Lectures

  • 5-Mar-07

Imaging in random media

I will present an overview of some recently developed methods for imaging with array and distributed sensors when the environment between the objects to be imaged and the sensors is complex and only partially known to the imager. This brings in mo   more››

Simon Fraser University

  • 2-Mar-07

Stable seismic data recovery

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››

University of British Columbia

  • 1-Mar-07

Almost-primes represented by quadratic polynomials

Dirichlet's theorem on primes in arithmetic progressions characterizes those linear polynomials which take on prime values infinitely often. However, this is where the current state of knowledge ends. For the case of polynomials with higher degree   more››

University of British Columbia

  • 1-Mar-07

Goldton-Yildirim-Pintz and small gaps between primes

I'll give an expository talk, following the recent article of Soundararajan, on the theorem of Goldston, Yildirim, and Pintz that there are infinitely many primes p such that the next prime q satisfies q – p = o(log p).   more››

University of British Columbia

  • 28-Feb-07

On Card Shuffling

I will talk about some famous results of Bayer and Diaconis (1992) which permit a rigorous answer to the following question: given a deck of n cards, how many times should it be shuffled so that the deck is in approximately random order? The goal   more››

University of British Columbia

  • 28-Feb-07

On braided and ordinary Hopf algebras

Braided Hopf algebras occur naturally in the structure theory of ordinary Hopf algebras. I will show how they arise in this context and how they can be used to construct (and possibly to classify) ordinary finite dimensional Hopf algebras.   more››

University of Alberta

  • 27-Feb-07

Littlewood-Richardson coefficients: Reduction formulae and a conjecture by King, Tollu and Toumazet

Littlewood-Richardson coefficients are structural constants of the cohomology ring of Grassmannians and the ring of Schur functions, and they are counted by the number of skew tableaux with certain properties. In this talk, we introduce well   more››

University of British Columbia

  • 27-Feb-07

Detecting Spillover: A dynamical systems modeling approach to glutamatergic synaptic signaling

The connectivity of neurons in the hippocampus depends in part on whether neurotransmitter from one release site can leak out and activate receptors in another synapse or extrasynaptic patch. The existence of such 'spillover' is under debate in th   more››

University of British Columbia

  • 23-Feb-07

Twisted K-theory (old and new), Part II

Twisted K-theory in terms of Banach algebras and Fredholm operators in an Hilbert space. Some computations.   more››

University of British Columbia

  • 23-Feb-07

Modelling biofilm growth in a porous medium with application in bioremediation

Studies on bioremediation in a porous medium have mainly focused on wastewater treatment. The interest in these investigations has focused on optimising degradation rates and substrate loading. Pore clogging has not been studied thoroughly. When p   more››

Simon Fraser University

  • 22-Feb-07

Complexity of Dependencies at the Syntactic Level and at the Discourse Level

Aravind K. Joshi is, at present, the Henry Salvatori Professor of Computer and Cognitive Science at the University of Pennsylvania. He served as the Director of the Institute for Research in Cognitive Science (IRCS) at the University of Pennsylvan   more››

Simon Fraser University

  • 21-Feb-07

Twisted K-theory (old and new), Part I

The Brauer group of a space and of a finite group. How are they related to K-theory?   more››

University of British Columbia

  • 19-Feb-07

The Reality of Computer Models: Statistics and Virtual Science

Computer models are imperfect representations of real phenomena. An austere view is that validating a model cannot be done, the "primary value of models is heuristic: models are representations, useful for guiding further study but not suscep   more››

University of Alberta

  • 16-Feb-07
  • 16-Feb-07

Homological Stability, Part II

Homological stability theorems have been proved for many families of groups like symmetric groups, linear groups, mapping class groups of surfaces and of 3-manifolds. I will review some examples and explain how such theorems are proved. As a more   more››

University of British Columbia

  • 16-Feb-07

Smooth Surfaces and Sharp Junctions

Because of their ability to form blends, respond to contact and produce both organic shapes as well as man made objects, implicit surfaces have the potential for uses other than the traditional clouds and water droplets. Models can be built with e   more››

University of British Columbia

  • 15-Feb-07

On Robust Utility Maximization

We study the problem of optimal investment in incomplete markets, robust with respect to stopping times. We work on a Brownian motion framework and the stopping times are adapted to the Brownian filtration. Robustness can only be achieved for loga   more››

University of British Columbia

  • 14-Feb-07

The lace expansion and the enumeration of self-avoiding walks

The lace expansion is an elegant combinatorial construction that provides a recursion relation for the number of self-avoiding walks. We first give an introduction to the lace expansion, and then explain how it has been used recently (in joint wor   more››

University of British Columbia