{ "id": "cond-mat/9709082", "version": "v1", "published": "1997-09-05T20:47:00.000Z", "updated": "1997-09-05T20:47:00.000Z", "title": "Violation of Scaling in the Contact Process with Quenched Disorder", "authors": [ "Ronald Dickman", "Adriana G. Moreira" ], "comment": "13 pages, revtex, 7 postscript figures", "doi": "10.1103/PhysRevE.57.1263", "categories": [ "cond-mat.stat-mech" ], "abstract": "We study the two-dimensional contact process (CP) with quenched disorder (DCP), and determine the static critical exponents beta and nu_perp. The dynamic behavior is incompatible with scaling, as applied to models (such as the pure CP) that have a continuous phase transition to an absorbing state. We find that the survival probability (starting with all sites occupied), for a finite-size system at critical, decays according to a power law, as does the off-critical density autocorrelation function. Thus the critical exponent nu_parallle, which governs the relaxation time, is undefined, since the characteristic relaxation time is itself undefined. The logarithmic time-dependence found in recent simulations of the critical DCP [Moreira and Dickman, Phys. Rev. E54, R3090 (1996)] is further evidence of violation of scaling. A simple argument based on percolation cluster statistics yields a similar logarithmic evolution.", "revisions": [ { "version": "v1", "updated": "1997-09-05T20:47:00.000Z" } ], "analyses": { "keywords": [ "quenched disorder", "percolation cluster statistics yields", "two-dimensional contact process", "similar logarithmic evolution", "characteristic relaxation time" ], "tags": [ "journal article" ], "publication": { "publisher": "APS", "journal": "Phys. Rev. E" }, "note": { "typesetting": "RevTeX", "pages": 13, "language": "en", "license": "arXiv", "status": "editable" } } }