{ "id": "1006.0875", "version": "v1", "published": "2010-06-04T12:02:08.000Z", "updated": "2010-06-04T12:02:08.000Z", "title": "Localization for (1+1)-dimensional pinning models with $(\\nabla + Δ)$-interaction", "authors": [ "Martin Borecki", "Francesco Caravenna" ], "comment": "13 pages, 1 figure", "categories": [ "math.PR" ], "abstract": "We study the localization/delocalization phase transition in a class of directed models for a homogeneous linear chain attracted to a defect line. The self-interaction of the chain is of mixed gradient and Laplacian kind, whereas the attraction to the defect line is of $\\delta$-pinning type, with strength $\\epsilon \\geq 0$. It is known that, when the self-interaction is purely Laplacian, such models undergo a non-trivial phase transition: to localize the chain at the defect line, the reward $\\epsilon$ must be greater than a strictly positive critical threshold $\\epsilon_c > 0$. On the other hand, when the self-interaction is purely gradient, it is known that the transition is trivial: an arbitrarily small reward $\\epsilon > 0$ is sufficient to localize the chain at the defect line ($\\epsilon_c = 0$). In this note we show that in the mixed gradient and Laplacian case, under minimal assumptions on the interaction potentials, the transition is always trivial, that is $\\epsilon_c = 0$.", "revisions": [ { "version": "v1", "updated": "2010-06-04T12:02:08.000Z" } ], "analyses": { "subjects": [ "60K35", "82B41", "60J05" ], "keywords": [ "defect line", "pinning models", "localization/delocalization phase transition", "self-interaction", "mixed gradient" ], "note": { "typesetting": "TeX", "pages": 13, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2010arXiv1006.0875B" } } }