{ "id": "1803.05887", "version": "v1", "published": "2018-03-15T17:40:41.000Z", "updated": "2018-03-15T17:40:41.000Z", "title": "Coulomb-gas electrostatics controls large fluctuations of the KPZ equation", "authors": [ "Ivan Corwin", "Promit Ghosal", "Alexandre Krajenbrink", "Pierre Le Doussal", "Li-Cheng Tsai" ], "comment": "6 pages + 7 pages of supplementary material; 2 figures", "categories": [ "cond-mat.stat-mech", "math-ph", "math.MP", "math.PR" ], "abstract": "We establish a large deviation principle for the Kardar-Parisi-Zhang (KPZ) equation, providing precise control over the left tail of the height distribution for narrow wedge initial condition. Our analysis exploits an exact connection between the KPZ one-point distribution and the Airy point process -- an infinite particle Coulomb-gas which arises at the spectral edge in random matrix theory. We develop the large deviation principle for the Airy point process and use it to compute, in a straight-forward and assumption-free manner, the KPZ large deviation rate function in terms of an electrostatic problem (whose solution we evaluate). This method also applies to the half-space KPZ equation, showing that its rate function is half of the full-space rate function. In addition to these long-time estimates, we provide rigorous proof of finite-time tail bounds on the KPZ distribution which demonstrate a crossover between exponential decay with exponent $3$ (in the shallow left tail) to exponent $5/2$ (in the deep left tail). The full-space KPZ rate function agrees with the one computed in Sasorov et al. [J. Stat. Mech, 063203 (2017)] via a WKB approximation analysis of a non-local, non-linear integro-differential equation generalizing Painlev\\'e II which Amir et al. [Comm. Pure Appl. Math. 64, 466 (2011)] related to the KPZ one-point distribution.", "revisions": [ { "version": "v1", "updated": "2018-03-15T17:40:41.000Z" } ], "analyses": { "keywords": [ "coulomb-gas electrostatics controls large fluctuations", "kpz equation", "large deviation rate function", "integro-differential equation generalizing painleve", "left tail" ], "note": { "typesetting": "TeX", "pages": 6, "language": "en", "license": "arXiv", "status": "editable" } } }