{ "id": "2301.03562", "version": "v1", "published": "2023-01-09T18:27:46.000Z", "updated": "2023-01-09T18:27:46.000Z", "title": "(Non-)amenability of $\\mathcal B(E)$ and Banach space geometry", "authors": [ "Matthew Daws", "Matthias Neufang" ], "comment": "20 pages", "categories": [ "math.FA" ], "abstract": "Let $E$ be a Banach space, and $\\mathcal B(E)$ the algebra of all bounded linear operators on $E$. The question of amenability of $\\mathcal B(E)$ goes back to Johnson's seminal memoir \\cite{johnson} from 1972. We present the first general criteria applying to very wide classes of Banach spaces, given in terms of the Banach space geometry of $E$, which imply that $\\mathcal B(E)$ is non-amenable. We cover all spaces for which this is known so far (with the exception of one particular example), with much shorter proofs, such as $\\ell_p$ for $p \\in [1, \\infty]$ and $c_0$, but also many new spaces: the numerous classes of spaces covered range from all $\\mathcal{L}_p$-spaces for $p \\in (1, \\infty)$ to Lorentz sequence spaces and reflexive Orlicz sequence spaces, to the Schatten classes $S_p$ for $p \\in [1,\\infty]$, and to the James space $J$, the Schlumprecht space $S$, and the Tsirelson space $T$, among others. Our approach also highlights the geometric difference to the only space for which $\\mathcal B(E)$ \\emph{is} known to be amenable, the Argyros--Haydon space, which solved the famous scalar-plus-compact problem.", "revisions": [ { "version": "v1", "updated": "2023-01-09T18:27:46.000Z" } ], "analyses": { "keywords": [ "banach space geometry", "amenability", "johnsons seminal memoir", "reflexive orlicz sequence spaces", "lorentz sequence spaces" ], "note": { "typesetting": "TeX", "pages": 20, "language": "en", "license": "arXiv", "status": "editable" } } }