{ "id": "1909.04874", "version": "v1", "published": "2019-09-11T06:57:22.000Z", "updated": "2019-09-11T06:57:22.000Z", "title": "Approximate semi-amenability of Banach algebras", "authors": [ "M. Shams Kojanaghi", "K. Haghnejad Azar", "M. R. Mardanbeigi" ], "categories": [ "math.FA" ], "abstract": "Let $\\mathfrak{A}$ be a Banach algebra, and $\\mathcal{X}$ a Banach $\\mathfrak{A}$-bimodule. A bounded linear mapping $\\mathcal{D}:\\mathfrak{A}\\rightarrow \\mathcal{X}$ is approximately semi-inner derivation if there eixist nets $(\\xi_{\\alpha})_{\\alpha}$ and $(\\mu_{\\alpha})_{\\alpha}$ in $\\mathcal{X}$ suh that, for each $a\\in\\mathfrak{A}$, $\\mathcal{D}(a)=\\lim_{\\alpha}(a.\\xi_{\\alpha}-\\mu_{\\alpha}.a)$. $\\mathfrak{A}$ is called approximately semi-amenable if for every Banach $\\mathfrak{A}$-bimodule $\\mathcal{X}$, every $\\mathcal{D}\\in\\mathcal{Z}^{1}(\\mathfrak{A},\\mathcal{X}^{*})$ is approximtely semi-inner. There are some Banach algebras which are approximately semi-amenable, but not approximately amenable. In this manuscript, we investigate some properties of approximate semi-amenability of Banach algebras. Also in Theorem \\ref{ee} we prove the approximate semi-amenability of Segal algebras on a locally compact, SIN group $G$.", "revisions": [ { "version": "v1", "updated": "2019-09-11T06:57:22.000Z" } ], "analyses": { "keywords": [ "banach algebra", "approximate semi-amenability", "sin group", "segal algebras", "eixist nets" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable" } } }