Tue, 01 Dec 2015
15:00

L1

Data Assimilation for Weather Forecasting: Reducing the Curse of Dimensionality

Professor Philippe Toint

(University of Namur)

Abstract

Weather prediction and, more generally, data assimilation in earth sciences, set a significant computing challenge 

because the size of the problem involved is very large.  The talk discusses algorithmic aspects related to the numerical 

solution of such problems and, in particular, focusses on how the lower dimensionality of the (dual) observation space 

may be used to advantage for computing a primal solution.  This is achieved both by adapting the preconditioned 

conjugate gradient and trust-region algorithms to dual space and by reducing the dimensionality of the latter as much 

as possible using observation hierarchies.

 

 

Mon, 30 Nov 2015

17:00 - 18:00

L1

Slightly Rubbish Modular Ax-Lindemann

Haden Spence

(Oxford University)

Abstract

In quite an elementary, hands-on talk, I will discuss some Ax-Lindemann type results in the setting of modular functions.  There are some very powerful results in this area due to Pila, but in nonclassical variants we have only quite weak results, for a rather silly reason to be discussed in the talk.