{ "id": "1403.7268", "version": "v2", "published": "2014-03-28T01:39:59.000Z", "updated": "2014-11-25T21:09:50.000Z", "title": "Critical two-point function of the 4-dimensional weakly self-avoiding walk", "authors": [ "Roland Bauerschmidt", "David C. Brydges", "Gordon Slade" ], "comment": "26 pages, revised version, will appear in Commun. Math. Phys", "categories": [ "math-ph", "math.DS", "math.MP", "math.PR" ], "abstract": "We prove $|x|^{-2}$ decay of the critical two-point function for the continuous-time weakly self-avoiding walk on $\\mathbb{Z}^d$, in the upper critical dimension $d=4$. This is a statement that the critical exponent $\\eta$ exists and is equal to zero. Results of this nature have been proved previously for dimensions $d \\geq 5$ using the lace expansion, but the lace expansion does not apply when $d=4$. The proof is based on a rigorous renormalisation group analysis of an exact representation of the continuous-time weakly self-avoiding walk as a supersymmetric field theory. Much of the analysis applies more widely and has been carried out in a previous paper, where an asymptotic formula for the susceptibility is obtained. Here, we show how observables can be incorporated into the analysis to obtain a pointwise asymptotic formula for the critical two-point function. This involves perturbative calculations similar to those familiar in the physics literature, but with error terms controlled rigorously.", "revisions": [ { "version": "v1", "updated": "2014-03-28T01:39:59.000Z", "comment": "22 pages", "journal": null, "doi": null }, { "version": "v2", "updated": "2014-11-25T21:09:50.000Z" } ], "analyses": { "subjects": [ "82B28", "97K99", "37A60" ], "keywords": [ "critical two-point function", "continuous-time weakly self-avoiding walk", "lace expansion", "supersymmetric field theory", "rigorous renormalisation group analysis" ], "publication": { "doi": "10.1007/s00220-015-2353-5", "journal": "Communications in Mathematical Physics", "year": 2015, "month": "Aug", "volume": 338, "number": 1, "pages": 169 }, "note": { "typesetting": "TeX", "pages": 26, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "2015CMaPh.338..169B" } } }