arXiv subjects

Juergen Geiser

Publications and source records attributed to Juergen Geiser.

22 records · Page 2Linked to original sources

arXiv2012

Multiscale Splitting method for Boltzmann-Poisson Equation: Application for Dynamic of Electrons

In this paper we present a model based on dynamics of the electrons in the plasma using a simplified Boltzmann equation coupled with a Poisson equation. The motivation arose to simulate active plasma resonance spectroscopy which is used for plasma diagnostic techniques, see [Braith2009]. We are interested on designing splitting methods to the model problem. First we reduce to a simplified transport equation and start to analyze the abstract Cauchy problem based on semi-groups. Second we extent to the coupled transport and kinetic model and apply the splitting ideas. The results are discussed with first numerical experiments to give discuss the numerical methods.

math.NA↗

arXiv2012

Splitting methods for Levitron Problems

In this paper we describe splitting methods for solving Levitron, which is motivated to simulate magnetostatic traps of neutral atoms or ion traps. The idea is to levitate a magnetic spinning top in the air repelled by a base magnet. The main problem is the stability of the reduced Hamiltonian, while it is not defined at the relative equilibrium. Here it is important to derive stable numerical schemes with high accuracy. For the numerical studies, we propose novel splitting schemes and analyze their behavior. We deal with a Verlet integrator and improve its accuracy with iterative and extrapolation ideas. Such a Hamiltonian splitting method, can be seen as geometric integrator and saves computational time while decoupling the full equation system. Experiments based on the Levitron model are discussed.

math-ph↗

arXiv2011

Multi-product expansion for Nonlinear Differential Equations

In this paper we discuss the extention of MPE methods to nonlinear differential equations. We concentrate on nonlinear systems of differential equations and generalize the recent MPE method, see the work of Chin and Geiser 2010.

math.DS↗

arXiv2009

Iterative operator-splitting methods for unbounded operators: Error analysis and examples

In this paper we describe an iterative operator-splitting method for unbounded operators. We derive error bounds for iterative splitting methods in the presence of unbounded operators and semigroup operators. Here mixed applications of hyperbolic and parabolic type are allowed and discussed in the applications. Mixed experiments are applied to ordinary differential equations and evolutionary Schrödinger equations.

math.NA↗