12:30
Models for subglacial floods during surface lake drainage events
Abstract
As temperatures are increasing, so is the presence of meltwater lakes sitting on the surface of the Greenland Ice Sheet. Such lakes have the possibility of draining through cracks in the ice to the bedrock. Observed discharge rates have found that these lakes can drain at three times the flow rate of Niagara Falls. Current models of subglacial drainage systems are unable to cope with such a large and sudden volume of water. This motivates the idea of a 'subglacial blister' which propagates and slowly dissipates underneath the ice sheet. We present a basic hydrofracture model for understanding this process, before carrying out a number of extensions to observe the effects of turbulence, topography, leak-off and finite ice thickness.
15:30
Foundations for derived analytic and differential geometry
Abstract
In this talk I will describe how bornological spaces give a foundation for derived geometries. This works over any Banach ring allowing to define analytic and differential geometry over the integers. I will discuss applications of this approach such as the representability of certain moduli spaces and Galois actions on the cohomology of differetiable manifolds admitting a \Q-form.
The Implcit Regularisation Effect of Stochastic Gradient Descent for the Ptychography Inverse Problem
Abstract
A Very Short Introduction to Ptychographic Image Reconstruction
Abstract
Dr Jari Fowkes will talk about; 'A Very Short Introduction to Ptychographic Image Reconstruction'
I will present a very short introduction to the mathematics behind the scientific imaging technique known as ptychography, starting with a brief overview of the physics model and the various simplifications required, before moving on to the main ptychography inverse problem and the three principal classes of optimization algorithms currently being used in practice.
16:00
The hyperbolic lattice point problem
Abstract