{ "id": "1607.05224", "version": "v1", "published": "2016-07-18T18:15:01.000Z", "updated": "2016-07-18T18:15:01.000Z", "title": "A note on dynamical models on random graphs and Fokker-Planck equations", "authors": [ "Sylvain Delattre", "Giambattista Giacomin", "Eric Luçon" ], "comment": "12 pages, 1 figure", "categories": [ "math.PR", "math-ph", "math.MP" ], "abstract": "We address the issue of the proximity of interacting diffusion models on large graphs with a uniform degree property and a corresponding mean field model, i.e. a model on the complete graph with a suitably renormalized interaction parameter. Examples include Erd\\H{o}s-R\\'enyi graphs with edge probability $p_n$, $n$ is the number of vertices, such that $\\lim_{n \\to \\infty}p_n n= \\infty$. The purpose of this note it twofold: (1) to establish this proximity on finite time horizon, by exploiting the fact that both systems are accurately described by a Fokker-Planck PDE (or, equivalently, by a nonlinear diffusion process) in the $n=\\infty$ limit; (2) to remark that in reality this result is unsatisfactory when it comes to applying it to systems with $N$ large but finite, for example the values of $N$ that can be reached in simulations or that correspond to the typical number of interacting units in a biological system.", "revisions": [ { "version": "v1", "updated": "2016-07-18T18:15:01.000Z" } ], "analyses": { "subjects": [ "82C20", "60K35" ], "keywords": [ "random graphs", "fokker-planck equations", "dynamical models", "finite time horizon", "nonlinear diffusion process" ], "note": { "typesetting": "TeX", "pages": 12, "language": "en", "license": "arXiv", "status": "editable" } } }