Mon, 27 Nov 2006
12:00
L3

Twisted Tori and (new) String Vacua

Ruben Minasian
(Ecole Polytechnique and Imperial)
Abstract

\\common\dfs\htdocs\www\maintainers\reception\enb\abstracts\string-theory\mt06\minasian.shtml

Thu, 23 Nov 2006

14:00 - 15:00
Comlab

Multilevel optimization and multigrid methods

Prof Philippe Toint
(University of Namur)
Abstract

Many large-scale optimization problems arise in the context of the discretization of infinite dimensional applications. In such cases, the description of the finite-dimensional problem is not unique, but depends on the discretization used, resulting in a natural multi-level description. How can such a problem structure be exploited, in discretized problems or more generally? The talk will focus on discussing this issue in the context of unconstrained optimization and in relation with the classical multigrid approach to elliptic systems of partial differential equations. Both theoretical convergence properties of special purpose algorithms and their numerical performances will be discussed. Perspectives will also be given.

Collaboration with S. Gratton, A. Sartenaer and M. Weber.