{ "id": "1906.03167", "version": "v1", "published": "2019-06-07T15:36:24.000Z", "updated": "2019-06-07T15:36:24.000Z", "title": "Random walk on the simple symmetric exclusion process", "authors": [ "Marcelo R. Hilário", "Daniel Kious", "Augusto Teixeira" ], "categories": [ "math.PR" ], "abstract": "We investigate the long-term behavior of a random walker evolving on top of the simple symmetric exclusion process (SSEP) at equilibrium, in dimension one. At each jump, the random walker is subject to a drift that depends on whether it is sitting on top of a particle or a hole, so that its asymptotic behavior is expected to depend on the density $\\rho \\in [0, 1]$ of the underlying SSEP. Our first result is a law of large numbers (LLN) for the random walker for all densities $\\rho$ except for at most two values $\\rho_-, \\rho_+ \\in [0, 1]$. The asymptotic speed we obtain in our LLN is a monotone function of $\\rho$. Also, $\\rho_-$ and $\\rho_+$ are characterized as the two points at which the speed may jump to (or from) zero. Furthermore, for all the values of densities where the random walk experiences a non-zero speed, we can prove that it satisfies a functional central limit theorem (CLT). For the special case in which the density is $1/2$ and the jump distribution on an empty site and on an occupied site are symmetric to each other, we prove a LLN with zero limiting speed. Finally, we prove similar LLN and CLT results for a different environment, given by a family of independent simple symmetric random walks in equilibrium.", "revisions": [ { "version": "v1", "updated": "2019-06-07T15:36:24.000Z" } ], "analyses": { "subjects": [ "60K35", "82B43", "60G55" ], "keywords": [ "simple symmetric exclusion process", "random walker", "independent simple symmetric random walks", "functional central limit theorem" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }