{ "id": "2305.13561", "version": "v1", "published": "2023-05-23T00:21:35.000Z", "updated": "2023-05-23T00:21:35.000Z", "title": "Binary fluid in a random medium and dimensional transmutation", "authors": [ "John Cardy" ], "comment": "4 pages", "categories": [ "cond-mat.stat-mech", "cond-mat.dis-nn" ], "abstract": "We propose a solution to the puzzle of dimensional reduction in the random field Ising model by studying the equivalent binary fluid in a random medium, and inverting the question by asking: to what random problem in $D\\!=\\!d+2$ dimensions does a pure system in $d$ dimensions correspond? For a model with purely repulsive interactions of finite range, we show that the mean density and other observables are equal to those of a similar model in $D$ dimensions, but with interactions and correlated disorder in the extra two dimensions of range $\\propto\\lambda$, in the limit as $\\lambda\\to\\infty$. There is no conflict with rigorous results that the finite range model with locally correlated disorder orders in $D=3$. Our argument avoids the use of replicas and perturbative field theory, instead being based on convergent cluster expansions. Although the result may be seen as a consequence of Parisi-Sourlas supersymmetry, it follows more directly from Kirchhoff's matrix-tree theorem.", "revisions": [ { "version": "v1", "updated": "2023-05-23T00:21:35.000Z" } ], "analyses": { "keywords": [ "random medium", "dimensional transmutation", "dimensions", "equivalent binary fluid", "random field ising model" ], "note": { "typesetting": "TeX", "pages": 4, "language": "en", "license": "arXiv", "status": "editable" } } }