Forthcoming Seminars

Mon, 17/01/2005
14:15 		Dr James Norris (University of Cambridge) Stochastic Analysis Seminar Add to calendar DH 3rd floor SR
Coagulation of Brownian particles
According to the Stokes-Einstein law, microscopic particles subject to intense bombardment by (much smaller) gas molecules perform Brownian motion with a diffusivity inversely proportion to their radius. Smoluchowski, shortly after Einstein's account of Brownian motion, used this model to explain the behaviour of a cloud of such particles when, in addition their diffusive motion, they coagulate on collision. He wrote down a system of evolution equations for the densities of particles of each size, in particular identifying the collision rate as a function of particle size. We give a rigorous derivation of (a spatially inhomogeneous generalization of) Smoluchowski's equations, as the limit of a sequence of Brownian particle systems with coagulation on collision. The equations are shown to have a unique, mass-preserving solution. A detailed limiting picture emerges describing the ancestral spatial tree of particles making up each particle in the current population. The limit is established at the level of these trees.
Mon, 17/01/2005
15:45 		Professor Enrique Andjel (Universite de Provence) Stochastic Analysis Seminar Add to calendar DH 3rd floor SR
Long Range Exclusion Process
Given a countable set of sites S an a transition matrix p(x,y) on that set, we consider a process of particles evolving on S according to the following rule: each particle waits an exponential time and then jumps following a Markov chain governed by p(x,y); the particle keeps jumping until it reaches an empty site where it remains for another exponential time. Unlike most interacting particle systems, this process fails to have the Feller property. This causes several technical difficulties to study it. We present a method to prove that certain measures are invariant for the process and exploit the Kolmogorov zero or one law to study some of its unusual path properties.
Mon, 17/01/2005
17:00 		Marc Lackenby Topology Seminar Add to calendar L3
Branched covers and large groups
/notices/events/abstracts/topology/lackenby.shtml
Mon, 17/01/2005
17:00 		R W Ogden (Glasgow) Applied Analysis and Mechanics Seminar Add to calendar L1
Nonlinear magnetoelasticity of magneto-sensitive solids
/notices/events/abstracts/applied-analysis/ht05/ogden.shtml
Tue, 18/01/2005
17:00 		Dr Sybille Schroll (Oxford) Algebra Seminar Add to calendar L1
On Alvis-Curtis duality and general linear groups
Thu, 20/01/2005
14:00 		Professor Nick Trefethen (Oxford) Computational Mathematics and Applications Add to calendar Comlab
Who invented the great numerical algorithms?
Thu, 20/01/2005
16:30 		Steven Galbraith (RHUL) Number Theory Seminar Add to calendar L3
The eta pairing
Fri, 21/01/2005
14:00 		Dr Natalia Janson (Dept. Mathematics, Loughborough University) Mathematical Biology Seminar Add to calendar L3
Forced synchronization in cardiovascular system
Mon, 24/01/2005
14:15 		Dr Benedict Haas (Department of Statistics, Oxford) Stochastic Analysis Seminar Add to calendar DH 3rd floor SR
The genealogy of self-similar fragmentations with a negative index as a continuum random tree
Fragmentation processes model the evolution of a particle that split as time goes on. When small particles split fast enough, the fragmentation is intensive and the initial mass is reduced to dust in finite time. We encode such fragmentation into a continuum random tree (CRT) in the sense of Aldous. When the splitting times are dense near 0, the fragmentation CRT is in turn encoded into a continuous (height) function. Under some mild hypotheses, we calculate the Hausdorff dimension of the CRT, as well as the maximal H
Mon, 24/01/2005
15:30 		Isar Stubbe (Louvain-La-Neuve) Analytic Topology in Mathematics and Computer Science Add to calendar L3
Dynamic Domains
Mon, 24/01/2005
15:45 		Professor Stanislov Smirnov (Royal Institute of Technology, Stockholm) Stochastic Analysis Seminar Add to calendar DH 3rd floor SR
Fractals and conformal invariance
It became apparent during the last decade that in several questions in classical complex analysis extremal configurations are fractal, making them very difficult to attack: it is not even clear how to construct or describe extremal objects. We will argue that the most promising approach is to consider conformally self-similar random configurations, which should be extremal almost surely.
Mon, 24/01/2005
17:00 		S Muller (Max-Planck-Institute for Mathematics in the Sciences, Leipzig) Applied Analysis and Mechanics Seminar Add to calendar L1
A variational model for dislocations in the line tension limit

For any corrections/updates to these listings, please contact seminars [-at-] maths [dot] ox [dot] ac [dot] uk.

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