{ "id": "2102.08901", "version": "v1", "published": "2021-02-17T17:49:40.000Z", "updated": "2021-02-17T17:49:40.000Z", "title": "Harmonic Analysis of Covariant Functions of Characters of Normal Subgroups", "authors": [ "Arash Ghaani Farashahi" ], "comment": "arXiv admin note: text overlap with arXiv:2102.07892", "categories": [ "math.FA" ], "abstract": "This paper presents a systematic study for abstract harmonic analysis on classical Banach spaces of covariant functions of characters of closed normal subgroups. Let $G$ be a locally compact group and $N$ be a closed normal subgroup of $G$. Suppose that $\\xi:N\\to\\mathbb{T}$ is a continuous character and $L_\\xi^1(G,N)$ is the $L^1$-space of all covariant functions of $\\xi$ on $G$. We showed that $L^1_\\xi(G,N)$ is isometrically isomorphic to a quotient space of $L^1(G)$. It is also proved that the dual space $L^1_\\xi(G,N)^*$ is isometrically isomorphic to $L^\\infty_\\xi(G,N)$. We then investigate some analytical aspects of the presented theory for the case of semi-direct product groups. The paper is concluded by realization of the theory in the case of some interesting examples.", "revisions": [ { "version": "v1", "updated": "2021-02-17T17:49:40.000Z" } ], "analyses": { "subjects": [ "43A15", "43A20", "43A85" ], "keywords": [ "covariant functions", "closed normal subgroup", "abstract harmonic analysis", "isometrically isomorphic", "semi-direct product groups" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }