For more information about this meeting, contact Yuxi Zheng, Kris Jenssen.

Title: | Multigrid methods in particle simulation |

Seminar: | CCMA Luncheon Seminar |

Speaker: | Matthias Bolten, University of Wuppertal |

Abstract: |

Particle simulation is an important tool in different ﬁelds of computational physics, e.g. plasma physics or biophysics. In all these ﬁelds interaction between atomistic particles is modelled via two- or multibody potentials and either the total system energy is calculated or the forces due to these potentials are integrated using some integration scheme. Typical simulations
include 105 – 109 particles, so the use of efficient codes is mandatory. Additionally, either a time integration or a Monte Carlo simulation is performed, so the forces or potentials have to be calculated many times. Short and long ranged potentials are distinguished: While for short ranged potentials optimal, i.e. complexity O(N ), where N is the number of particles, long ranged
potentials in principle require complexity O(N^2 ). One of the most common
long-ranged potentials is the Coulomb potential. As the quadratic complexity can be problematic for many applications, a lot of effort has been spent on the development of methods for long-ranged potentials, especially for the Coulomb potential.
During the last years we developed a multigrid-based method for the calculation of potentials and forces due to the Coulomb potential. The method works for both types of boundary conditions, i.e. periodic and open boundary conditions, and being based on multigrid it scales optimal. Additionally, the only type of error involved is due to discretization.
For large-scale simulation runs, the method for periodic boundary condition is fully parallelized and highly scalable.
In the talk, we will provide a short introduction into the problem, then the
multigrid-based method and the parallel version will be presented. We close
with numerical experiments and show the scaling behavior of the method. |

### Room Reservation Information

Room Number: | MB114 |

Date: | 03 / 05 / 2010 |

Time: | 12:00pm - 01:30pm |