{ "id": "1912.01753", "version": "v1", "published": "2019-12-04T00:45:36.000Z", "updated": "2019-12-04T00:45:36.000Z", "title": "A family of fractional diffusion equations derived from stochastic harmonic chains with long-range interactions", "authors": [ "Hayate Suda" ], "comment": "43 pages", "categories": [ "math.PR", "math-ph", "math.MP" ], "abstract": "We consider one-dimensional infinite chains of harmonic oscillators with stochastic perturbations and long-range interactions which have polynomial decay rate $|x|^{-\\theta}, x \\to \\infty, \\theta > 1$, where $x \\in \\mathbb{Z}$ is the interaction range. We prove that if $2< \\theta \\le 3$, then the time evolution of the macroscopic thermal energy distribution is superdiffusive and governed by a fractional diffusion equation with exponent $\\frac{3}{7-\\theta}$, while if $\\theta > 3$, then the exponent is $\\frac{3}{4}$. The threshold is $ \\theta = 3$ because the derivative of the dispersion relation diverges as $k \\to 0$ when $\\theta \\le 3$.", "revisions": [ { "version": "v1", "updated": "2019-12-04T00:45:36.000Z" } ], "analyses": { "keywords": [ "fractional diffusion equation", "stochastic harmonic chains", "long-range interactions", "macroscopic thermal energy distribution", "polynomial decay rate" ], "note": { "typesetting": "TeX", "pages": 43, "language": "en", "license": "arXiv", "status": "editable" } } }