{ "id": "math/9610215", "version": "v1", "published": "1996-10-17T00:00:00.000Z", "updated": "1996-10-17T00:00:00.000Z", "title": "Operators on $C(ω^α)$ which do not preserve $C(ω^α)$", "authors": [ "Dale E. Alspach" ], "categories": [ "math.FA" ], "abstract": "It is shown that if $\\alpha ,\\zeta $ are ordinals such that $1\\leq \\zeta <\\alpha <\\zeta \\omega ,$ then there is an operator from $C(\\omega ^{\\omega ^\\alpha })$ onto itself such that if $Y$ is a subspace of $C(\\omega ^{\\omega ^\\alpha })$ which is isomorphic to $C(\\omega ^{\\omega ^\\alpha })$ $,$ then the operator is not an isomorphism on $Y.$ This contrasts with a result of J. Bourgain that implies that there are uncountably many ordinals $\\alpha $ for which any operator from $C(\\omega ^{\\omega ^\\alpha })$ onto itself there is a subspace of $C(\\omega ^{\\omega ^\\alpha })$ which is isomorphic to $% C(\\omega ^{\\omega ^\\alpha })$ on which the operator is an isomorphism.", "revisions": [ { "version": "v1", "updated": "1996-10-17T00:00:00.000Z" } ], "analyses": { "subjects": [ "46B03" ], "keywords": [ "isomorphic", "isomorphism" ], "note": { "typesetting": "TeX", "pages": 0, "language": "en", "license": "arXiv", "status": "editable", "adsabs": "1996math.....10215A" } } }