Scientific Lectures

  • 3-Apr-07

Conservation of the combinatorial structure in genome

We investigate the problem of computing an evolution scenario based on genome rearrangements between two genomes modelized by synteny blocks, or in mathematical terms, sorting signed permutations by reversals. We consider the case of scenarios tha   more››

University of British Columbia

  • 3-Apr-07

Minimum Cuts and Maximum Area

The oldest competition for an optimal shape (area-maximizing) was won by the circle. We want to give the thousandth proof ! Then we measure the perimeter in different ways, which changes the problem (and has applications in medical i   more››

Simon Fraser University

  • 2-Apr-07

Asymptotic behavior at infinity of solutions of elliptic equations

The prototype problem is the behavior at infinity of all solutions of a linear elliptic equation that have finite L1 norm in a half cylinder 0<y, x in D,D a smoothly bounded domain. We assume that the coefficients of the elliptic operator,as we   more››

University of British Columbia

  • 2-Apr-07

Statistical Models for Global Processes

This talk explores some of the issues that arise in statistical modeling of atmospheric phenomena on a global scale, using total column ozone as measured by the satellite-based Total Ozone Mapping Spectrometer (TOMS) as a case study. A basic issue   more››

University of British Columbia

  • 30-Mar-07

A Phragmen-Lindelof and Saint Venant principle in harmonic analysis

Let S be a linear space of vector valued functions u(y) on the half-line whose values belong to some Banach space. We suppose that S is translation invariant; that is, if u(y) belongs to S, so does u(y+t) for all t>0. S is called 'interior comp   more››

University of Washington

  • 29-Mar-07

Fake 2-descent on the Jacobian of a genus-3 curve

For many questions in explicit arithmetic geometry of curves, one needs detailed information on the rational points of the Jacobian of the curve. A first step is to bound the free rank of the finitely generated group that they form. For hyperellip   more››

University of British Columbia

  • 29-Mar-07

Data Stream Processing with Resource Adaptive Computation

The problem of streaming data has gained importance in recent years because of advances in hardware technology. The ubiquitous presence of data streams in a number of practical domains has generated a lot of research in this area. Example applicat   more››

Simon Fraser University

  • 29-Mar-07

Portfolio optimization in a hidden Markov model for stock returns with jumps

In a market consisting of a money market and one stock with price process dS(t)=S(t)[a(t) dt + b dW(t) + g dM(t)] where W is a Wiener process and M is a compensated Poisson process, an agent invests his initial wealth in a portfolio to maxim   more››

University of British Columbia

  • 29-Mar-07

Variations on a theme of Stark

Zeta functions and L-functions contain arithmetic information when evaluated at special values, such as s = 0. In the 1970s, Stark conjectured that the derivatives of L-functions at s = 0 can be evaluated by certain algebraic units. Under certain cir   more››

University of British Columbia

  • 28-Mar-07

Matchings of exponential tail on coin flips in Z^d

We construct a translation-invariant matching between vertices of different labels of Bernoulli(1/2) percolation on Z^d, in such a way that the probability that a vertex is at distance > r from its pair decays as an exponential function of the   more››

University of British Columbia

  • 27-Mar-07

Reconstruction and subgaussian operator

Candes, Romberg and Tao recently studied problems of approximate and exact reconstruction of sparse signals from incomplete random measurements and related them to the eigenvalue behavior of submatrices of matrices of random measurements. In parti   more››

University of British Columbia

  • 26-Mar-07

The interface between Bayesian and frequentist statistics

Statistical theory is often categorized as either "Bayesian" or "frequentist", and statisticians often self-identify in the same categories. During the development of theoretical statistics as a separate field in the twentieth   more››

University of British Columbia

  • 23-Mar-07

Minimal determinants for the centres and topological centres of some

The algebraic centre of the uniformly continuous compactification GUC of an abelian locally compact group G is G itself. There is a stronger result: if u commutes with just two (carefully chosen) elements of   more››

University of Alberta

  • 22-Mar-07

The A-polynomial detects the trivial knot and other applications of character variety methods in 3-dimensional topology

William Thurston conjectured over twenty years ago that every compact hyperbolic 3-manifold whose boundary is a possibly empty union of tori is virtually fibred, that is, has a finite cover which fibres over the circle. If true, it provides a sign   more››

University of British Columbia

  • 22-Mar-07

The Role of Mathematics in Physical Ecology

The natural link between mathematics and ecology is evident in the field of physical ecology, which uses physical models to explore some fundamental issues. These include how aquatic organisms use the constraints imposed by physical environment to   more››

University of British Columbia

  • 22-Mar-07

Local Interaction Games with Random Matching

We state conditions for existence and uniqueness of equilibria in evolutionary models with an infinity of locally and globally interacting agents. Agents face repeated discrete choice problems. Their utility depends on the actions of some designat   more››

University of British Columbia

  • 21-Mar-07

Differentiability of Quadratic BSDEs

We consider Backward Stochastic Differential Equations (BSDE) with generators that grow quadratically in the control variable. In a more abstract setting, we first allow both the terminal condition and the generator to depend on a vector parameter   more››

University of British Columbia

  • 21-Mar-07

On families of virtually fibred Montesinos link exteriors

William Thurston conjectured over twenty years ago that every compact hyperbolic 3-manifold whose boundary is a possibly empty union of tori is virtually fibred, that is, has a finite cover which fibres over the circle. If true, it provides a sign   more››

University of British Columbia

  • 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››

University of British Columbia

  • 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››

University of British Columbia