{ "id": "1810.03580", "version": "v1", "published": "2018-10-08T17:03:10.000Z", "updated": "2018-10-08T17:03:10.000Z", "title": "Busemann functions and Gibbs measures in directed polymer models on $\\mathbb{Z}^2$", "authors": [ "Christopher Janjigian", "Firas Rassoul-Agha" ], "comment": "48 pages, 2 figures", "categories": [ "math.PR" ], "abstract": "We consider random walk in a space-time random potential, also known as directed random polymer measures, on the planer square lattice with nearest-neighbor steps and general i.i.d. weights on the vertices. We construct covariant cocycles and use them to prove new results on existence, uniqueness/non-uniqueness, and asymptotic directions of semi-infinite polymer measures (solutions to the Dobrushin-Lanford-Ruelle equations). We also prove non-existence of covariant or deterministically directed bi-infinite polymer measures. Along the way, we prove almost sure existence of Busemann function limits in directions where the limiting free energy has some regularity.", "revisions": [ { "version": "v1", "updated": "2018-10-08T17:03:10.000Z" } ], "analyses": { "subjects": [ "60K35", "60K37" ], "keywords": [ "directed polymer models", "gibbs measures", "space-time random potential", "busemann function limits", "planer square lattice" ], "note": { "typesetting": "TeX", "pages": 48, "language": "en", "license": "arXiv", "status": "editable" } } }