{ "id": "1902.01098", "version": "v1", "published": "2019-02-04T09:37:53.000Z", "updated": "2019-02-04T09:37:53.000Z", "title": "Regularity and inverse theorems for uniformity norms on compact abelian groups and nilmanifolds", "authors": [ "Pablo Candela", "Balázs Szegedy" ], "comment": "35 pages", "categories": [ "math.CO", "math.CA", "math.NT" ], "abstract": "We prove a general form of the regularity theorem for uniformity norms, and deduce a generalization of the Green-Tao-Ziegler inverse theorem, extending it to a class of compact nilspaces including all compact abelian groups and nilmanifolds. We derive these results from a structure theorem for cubic couplings, thereby unifying these results with the ergodic structure theorem of Host and Kra. The proofs also involve new results on nilspaces. In particular, we obtain a new stability result for nilspace morphisms. We also strengthen a result of Gutman, Manners and Varju, by proving that a k-step compact nilspace of finite rank is a toral nilspace (in particular, a connected nilmanifold) if and only if its k-dimensional cube set is connected. We also prove that if a morphism from a cyclic group of prime order into a compact finite-rank nilspace is sufficiently balanced (a quantitative form of multidimensional equidistribution), then the nilspace is toral.", "revisions": [ { "version": "v1", "updated": "2019-02-04T09:37:53.000Z" } ], "analyses": { "keywords": [ "compact abelian groups", "uniformity norms", "nilmanifold", "compact finite-rank nilspace", "ergodic structure theorem" ], "note": { "typesetting": "TeX", "pages": 35, "language": "en", "license": "arXiv", "status": "editable" } } }