{ "id": "0705.2648", "version": "v2", "published": "2007-05-18T09:03:05.000Z", "updated": "2007-08-07T08:51:07.000Z", "title": "Statistics of the Number of Zero Crossings : from Random Polynomials to Diffusion Equation", "authors": [ "Gregory Schehr", "Satya N. Majumdar" ], "comment": "4 pages, 3 figures. Minor changes. Accepted version in Phys. Rev. Lett", "journal": "Phys. Rev. Lett. 99, 060603 (2007)", "doi": "10.1103/PhysRevLett.99.060603", "categories": [ "cond-mat.stat-mech", "cond-mat.dis-nn", "math.PR" ], "abstract": "We consider a class of real random polynomials, indexed by an integer d, of large degree n and focus on the number of real roots of such random polynomials. The probability that such polynomials have no real root in the interval [0,1] decays as a power law n^{-\\theta(d)} where \\theta(d)>0 is the exponent associated to the decay of the persistence probability for the diffusion equation with random initial conditions in space dimension d. For n even, the probability that such polynomials have no root on the full real axis decays as n^{-2(\\theta(d) + \\theta(2))}. For d=1, this connection allows for a physical realization of real random polynomials. We further show that the probability that such polynomials have exactly k real roots in [0,1] has an unusual scaling form given by n^{-\\tilde \\phi(k/\\log n)} where \\tilde \\phi(x) is a universal large deviation function.", "revisions": [ { "version": "v2", "updated": "2007-08-07T08:51:07.000Z" } ], "analyses": { "subjects": [ "05.40.-a", "02.50.-r", "05.70.Ln", "82.40.Bj" ], "keywords": [ "diffusion equation", "zero crossings", "real random polynomials", "real root", "full real axis decays" ], "tags": [ "journal article" ], "publication": { "publisher": "APS", "journal": "Physical Review Letters", "year": 2007, "month": "Aug", "volume": 99, "number": 6, "pages": "060603" }, "note": { "typesetting": "TeX", "pages": 4, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2007PhRvL..99f0603S" } } }