Past

For a superprocess in a random environment in one dimensional space, a nonlinear stochastic partial differential equation is derived for its density by Dawson-Vaillancourt-Wang (2000). The joint continuity was left as an open problem. In this talk, we will give an affirmative answer to this problem.

• Simon Cotter presents:       “Chemical Fokker-Planck equation and multiscale modelling of (bio)chemical systems”
• Lian Duan presents:            “History matching problems using Bspline Parameterization”
• Chris Prior presents:          “Helices, tubes and the Fourier Transform”

We present an O(N logN) algorithm for the calculation of the first N coefficients in an expansion of an analytic function in Legendre polynomials. In essence, the algorithm consists of an integration of a suitably weighted function along an ellipse, a task which can be accomplished with Fast Fourier Transform, followed by some post-processing.

Hilbert Sixth Problem of Axiomatization of Physics is a problem of general nature and not of specific problem. We will concentrate on the kinetic theory; the relations between the Newtonian particle systems, the Boltzmann equation and the fluid dynamics. This is a rich area of applied mathematics and mathematical physics. We will illustrate the richness with some examples, survey recent progresses and raise open research directions.

Presentations by:

09.30 am Bernhard Langwallner Continuum limits of atomistic energies and new computational models of fracture

09.50 am Yasemin Sengul Well-posedness of dynamics

10.10 am Kostas Koumatos X-interfaces and nonclassical austenite-martensite interfaces

10.30 am Tim Squires Models for breast cancer and heart tissue

Abstract: Quantales are ordered algebras which can be thought of as pointfree noncommutative topologies. In recent years, their connections have been studied with fundamental notions in noncommutative geometry such as groupoids and C*-algebras. In particular, the setting of quantales corresponding to étale groupoids has been very well understood: a bijective correspondence has been defined between localic étale groupoids and inverse quantale frames. We present an equivalent but independent way of defining this correspondence for topological étale groupoids and we extend this correspondence to a non-étale setting.

Wound coils or rolls accumulate essentially flat strip compactly without folding or cutting and typically, strip is wound and unwound a number of times before its end use. The variety of material that is wound into coils or rolls is very extensive and includes magnetic tape, paper, cellophane, plastics, fabric and metals such as aluminium and steel.

Stresses wound into a coil provide its structural integrity via the frictional forces between the wraps. For a coil with inadequate inter-wrap pressure, the wraps may slip or telescope (causing surface scuffing) or the coil may slump and collapse. On the other hand, large internal stresses can cause increased creep and stress relaxation, collapse at the bore, stress wrinkling and rupture of the material in the coil.

Given the range of applications, it is not surprising that the literature on calculating stresses in wound coils is large and has a long history, which goes back at least to the wire winding of gun barrels. However the basic approach of the resulting accretion models, where the residual stress is recalculated each time a layer is added, has remained essentially the same. In this talk, we take a radically different approach in analysing the winding stresses in coils. Instead of the traditional method, we seek to deduce a winding policy that will achieve a target distribution of residual stresses within a coil. In this way, optimising the coiling tension profile is much more straight-forward, by

* Specifying the residue stresses required to avoid operational problems, tight-bore collapses, and other issues such as scuffing, then

* Determining the winding tension profile to produce the required residue stresses.

Strong explosive volcanic eruptions could inject in the lower stratosphere million tons of SO2, which being converted to sulfate aerosols, affect radiative balance of the planet for a few years. During this period the volcanic radiative forcing dominates other forcings producing distinct detectable climate responses. Therefore volcanic impacts provide invaluable natural test of climate nonlinearities and feedback mechanisms. In this talk I will overview volcanic impacts on tropospheric and strsatospheric temperature, ozone, high-latitude circulation, stratosphere-troposphere dynamic interaction, and focus on the long-term volcanic effect on ocean heat content and sea level.

This workshop is half-seminar, half-workshop. \\ \\ HSBC have an on-going problem and they submitted a proposal for an MSc in Applied Stats project on this topic. Unfortunately, the project was submitted too late for this cohort of students. Eurico will talk about "the first approach at the problem" but please be aware that it is an open problem which requires further work. Eurico's abstract is as follows. \\ \\

This article examines modelling yield curves through chaotic dynamical systems whose dynamics can be unfolded using non-linear embeddings in higher dimensions. We then refine recent techniques used in the state space reconstruction of spatially extended time series in order to forecast the dynamics of yield curves.

We use daily LIBOR GBP data (January 2007-June 2008) in order to perform forecasts over a 1-month horizon. Our method seems to outperform random walk and other benchmark models on the basis of mean square forecast error criteria.

In this talk I will discuss "motivic" Donaldson-Thomas invariants, following the now not-so-recent paper of Kontsevich and Soibelman on this subject. I will, in particular, present some understanding of the mysterious notion of "orientation data," and present some recent work. I will of course do my best to make this talk "accessible," though if you don't know what a scheme or a category is it will probably make you cry.

The second talk will present conjectural motivic generalizations

of ADHM sheaf invariants as well as their wallcrossing formulas.

It will be shown that these conjectures yield recursive formulas

for Poincare and Hodge polynomials of moduli spaces of Hitchin

pairs. It will be checked in many concrete examples that this recursion relation is in agreement with previous results of Hitchin, Gothen, Hausel and Rodriguez-Villegas.

The first talk will present a construction of equivariant

virtual counting invariants for certain quiver sheaves on a curve, called ADHM sheaves. It will be shown that these invariants are related to the stable pair theory of Pandharipande and Thomas in a specific stability chamber. Wallcrossing formulas will be derived using the theory of generalized Donaldson-Thomas invariants of Joyce and Song.

This talk will begin with an introduction to calibrations and calibrated submanifolds. Calibrated geometry generalizes Wirtinger's inequality in Kahler geometry by considering k-forms which are analogous to the Kahler form. A famous one-line proof shows that calibrated submanifolds are volume minimizing in their homology class. Our examples of manifolds with a calibration will come from complex geometry and from manifolds with special holonomy.

We will then discuss the deformation theory of the calibrated submanifolds in each of our examples and see how they differ from the theory of complex submanifolds of Kahler manifolds.