**
Mardi 27 février 2018
de
11:00 à
12:00
, Lieu : Salle de réunion bâtiment 17
**

**Orateur** : Kostas Moraitis

**Résumé** : Many astrophysical applications require the computation of the scalar and/or vector potential of a vector field. In our case, the goal is to be able to properly compute magnetic helicity in the solar context, something that requires the computation of a potential magnetic field. This can be accomplished with the solution of Laplace’s equation under Neumann boundary conditions in the whole boundary. While in Cartesian coordinates standard solvers exist, in spherical coordinates, a usual natural coordinate system for celestial bodies, and finite volumes, this problem is not as trivial as in other instances of Laplace’s equation. The solution to this problem is going to be discussed in this talk. We will first define the geometry of the problem and the relevant equations involved in it, and then describe the details of the method that was used for the solution, as well as other situations where such methods can be useful.