{ "id": "1609.07084", "version": "v1", "published": "2016-09-22T17:47:34.000Z", "updated": "2016-09-22T17:47:34.000Z", "title": "Average Free-Energy of Directed Polymers and Interfaces in Random Media", "authors": [ "R. Acosta Diaz", "C. D. Rodríguez-Camargo", "N. F. Svaiter" ], "comment": "19 pages. arXiv admin note: text overlap with arXiv:1603.05919", "categories": [ "cond-mat.stat-mech", "cond-mat.soft" ], "abstract": "We consider first the field theory formulation for a directed polymer in the presence of a quenched disorder. To obtain the average free-energy of this system we use the distributional zeta-function method. The distributional zeta-function is a complex function whose derivative at the origin yields the average free-energy of the system as the sum of two contributions: the first one is a series in which all the integer moments of the partition function of the model contribute; the second one, which can not be written as a series of the integer moments, but can be made as small as desired. Using the saddle-point equations of the model, and the replica symmetry ansatz, we obtain that the numbers of terms in the series representation for the average free-energy depends on the temperature of the system. Next, the field theory formulation of an interface in a quenched random potential is considered. Also using the results obtained from the distributional zeta-function method, the average free-energy of this system is presented. The $k$-th term of the series that defines the average free-energy represents an Euclidean field theory for a $k$-component Gaussian scalar field.", "revisions": [ { "version": "v1", "updated": "2016-09-22T17:47:34.000Z" } ], "analyses": { "keywords": [ "directed polymer", "random media", "distributional zeta-function method", "field theory formulation", "component gaussian scalar field" ], "note": { "typesetting": "TeX", "pages": 19, "language": "en", "license": "arXiv", "status": "editable" } } }