774 research outputs found
Indirect Interaction of Magnetic Domain Walls
We calculate the electron-mediated exchange interaction between two domain
walls in magnetic wires. This corresponds to the equilibrium regime and,
therefore, the interaction can be additionally controlled by an electric
current. The exchange interaction is long ranged and oscillates as a function
of the distance between the walls. It also depends oscillatory on the
polarization angle of the walls, having the maximum value for collinear
polarization.Comment: 3 pages, 3 figure
The multi-scale dust formation in substellar atmospheres
Substellar atmospheres are observed to be irregularly variable for which the
formation of dust clouds is the most promising candidate explanation. The
atmospheric gas is convectively unstable and, last but not least, colliding
convective cells are seen as cause for a turbulent fluid field. Since dust
formation depends on the local properties of the fluid, turbulence influences
the dust formation process and may even allow the dust formation in an
initially dust-hostile gas. A regime-wise investigation of dust forming
substellar atmospheric situations reveals that the largest scales are
determined by the interplay between gravitational settling and convective
replenishment which results in a dust-stratified atmosphere. The regime of
small scales is determined by the interaction of turbulent fluctuations.
Resulting lane-like and curled dust distributions combine to larger and larger
structures. We compile necessary criteria for a subgrid model in the frame of
large scale simulations as result of our study on small scale turbulence in
dust forming gases.Comment: 22 Pages, 5 Figures, to appear in "Analysis and Numerics of
Conservation Laws", ed. G. Warnecke (Springer-Verlag
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