Concatenating Variational Principles and the Kinetic Stress-Energy-Momentum Tensor
We show how to "concatenate" variational principles over dierent 
bases into one over a single base, thereby providing a unied Lagrangian 
treatment of interacting systems. As an example we study a Klein{ 
Gordon eld interacting with a mesically charged particle. We employ 
our method to give a novel group-theoretic derivation of the kinetic 
stress-energy-momentum tensor density corresponding to the particle.
Generic global solutions of the relativistic Vlasov-Maxwell system of plasma physics
The behaviour of classical solutions of the relativistic Vlasov-Maxwell system under small perturbations of the initial data is investigated. First it is shown that the solutions depend continuoussly on the initial data with respect to various norms. The main result is on global solutions: A global solution whose electromagnetic field decays in a certain way for large times is shown to remain global under small perturbations of the initial data and to retain the decay behaviour of the field. Therefore, such global solutions are generic. This result implies the existence of global solutions for nearly symmetric initial data.
Monte Carlo simulations of magnetovolume instabilities in anti-Invar systems
We perform constant pressure Monte Carlo simulations of a spin-analogous model which describes coupled spatial and magnetic degrees of freedom on an fcc lattice. Our calculations qualitatively reproduce magnetovolume effects observed in some rare earth manganese compounds, especially in the anti-Invar material YMn2. These are a sudden collapse of the magnetic moment which is connected with a huge volume change, and a largely enhanced thermal expansion coefficient.