{ "id": "1603.06823", "version": "v1", "published": "2016-03-22T15:15:26.000Z", "updated": "2016-03-22T15:15:26.000Z", "title": "Advective-diffusive motion on large scales from small-scale dynamics with an internal symmetry", "authors": [ "Raffaele Marino", "Erik Aurell" ], "comment": "20 pages, 4 figures", "categories": [ "cond-mat.stat-mech" ], "abstract": "We consider coupled diffusions in $n$-dimensional space and on a compact manifold and the resulting effective advective-diffusive motion on large scales in space. The effective drift (advection) and effective diffusion are determined as a solvability conditions in a multi-scale analysis. As an example we consider coupled diffusions in $3$-dimensional space and on the group manifold $SO(3)$ of proper rotations, generalizing results obtained by H. Brenner (1981). We show in detail how the analysis can be conveniently be carried out using local charts and invariance arguments. As a further example we consider coupled diffusions in $2$-dimensional complex space and on the group manifold $SU(2)$. We show that although the local operators may be the same as for $SO(3)$, due to the global nature of the solvability conditions the resulting diffusion will be different, and generally more isotropic.", "revisions": [ { "version": "v1", "updated": "2016-03-22T15:15:26.000Z" } ], "analyses": { "keywords": [ "large scales", "advective-diffusive motion", "small-scale dynamics", "internal symmetry", "coupled diffusions" ], "note": { "typesetting": "TeX", "pages": 20, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2016arXiv160306823M" } } }