{ "id": "1302.2452", "version": "v1", "published": "2013-02-11T11:26:41.000Z", "updated": "2013-02-11T11:26:41.000Z", "title": "Exact distributions of the number of distinct and common sites visited by N independent random walkers", "authors": [ "Anupam Kundu", "Satya N. Majumdar", "Gregory Schehr" ], "comment": "5 pages, 3 figures", "journal": "Phys. Rev. Lett. 110, 220602 (2013)", "doi": "10.1103/PhysRevLett.110.220602", "categories": [ "cond-mat.stat-mech", "cond-mat.dis-nn", "math.PR" ], "abstract": "We study the number of distinct sites S_N(t) and common sites W_N(t) visited by N independent one dimensional random walkers, all starting at the origin, after t time steps. We show that these two random variables can be mapped onto extreme value quantities associated to N independent random walkers. Using this mapping, we compute exactly their probability distributions P_N^d(S,t) and P_N^d(W,t) for any value of N in the limit of large time t, where the random walkers can be described by Brownian motions. In the large N limit one finds that S_N(t)/\\sqrt{t} \\propto 2 \\sqrt{\\log N} + \\widetilde{s}/(2 \\sqrt{\\log N}) and W_N(t)/\\sqrt{t} \\propto \\widetilde{w}/N where \\widetilde{s} and \\widetilde{w} are random variables whose probability density functions (pdfs) are computed exactly and are found to be non trivial. We verify our results through direct numerical simulations.", "revisions": [ { "version": "v1", "updated": "2013-02-11T11:26:41.000Z" } ], "analyses": { "subjects": [ "05.40.Fb", "02.50.-r", "05.40.Jc" ], "keywords": [ "independent random walkers", "common sites", "exact distributions", "random variables", "probability density functions" ], "tags": [ "journal article" ], "publication": { "publisher": "APS", "journal": "Physical Review Letters", "year": 2013, "month": "May", "volume": 110, "number": 22, "pages": 220602 }, "note": { "typesetting": "TeX", "pages": 5, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2013PhRvL.110v0602K" } } }