{ "id": "1909.09873", "version": "v1", "published": "2019-09-21T19:01:10.000Z", "updated": "2019-09-21T19:01:10.000Z", "title": "Some harmonic analysis on commutative nilmanifolds", "authors": [ "Andrea L. Gallo", "Linda. V. Saal" ], "categories": [ "math.FA", "math.RT" ], "abstract": "In this work, we consider a family of Gelfand pairs $(K \\ltimes N, N)$ (in short $(K,N)$) where $N$ is a two step nilpotent Lie group, and $K$ is the group of orthogonal automorphisms of $N$. This family has a nice analytic property: almost all these 2-step nilpotent Lie group have square integrable representations. In this cases, following Moore-Wolf's theory, we find an explicit expression for the inversion formula of $N$, and as a consequence, we decompose the regular action of $K \\ltimes N$ on $L^{2}(N)$. This result completes the analysis carried out by Wolf, where the inversion formula is obtained in the case that $N$ has not square integrable representation. When $N$ is the Heisenberg group, we obtain the decomposition of $L^{2}(N)$ under the action of $K \\ltimes N$ for all $K$ such that $(K,N)$ is a Gelfand pair. Finally, we also give a parametrization for the generic spherical functions associated to the pair $(K,N)$, and we give an explicit expression for these functions in some cases.", "revisions": [ { "version": "v1", "updated": "2019-09-21T19:01:10.000Z" } ], "analyses": { "subjects": [ "43A80", "22E25" ], "keywords": [ "harmonic analysis", "commutative nilmanifolds", "square integrable representation", "step nilpotent lie group", "explicit expression" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }