RT info:eu-repo/semantics/article T1 Cesàro bounded operators in Banach spaces A1 Bermúdez De León, Teresa De Jesús A1 Bonilla Ramírez, Antonio Lorenzo A1 Müller, V. A1 Peris, A. K1 Banach spaces AB Westudyseveralnotionsofboundedness foroperators. It isknownthat anypowerboundedoperatorisabsolutelyCes`aroboundedandstronglyKreiss bounded(inparticular,uniformlyKreissbounded).Theconversesdonothold ingeneral. Inthisnote,wegiveexamplesoftopologicallymixing(hence,not powerbounded)absolutelyCes`aroboundedoperatorson p(N),1≤p<∞, andprovideexamplesofuniformlyKreissboundedoperatorswhicharenot absolutelyCes`arobounded.Theseresultscomplementafewknownexamples (see [27] and [2]). Wealsoobtainacharacterizationof powerboundedoperatorswhichgeneralizesaresultofVanCasteren [32]. In [2]Alemanand SuciuaskedifeveryuniformlyKreissboundedoperatorTonaBanachspace satisfiesthat limn→∞ Tn n =0.WesolvethisquestionforHilbertspaceoperatorsand,moreover,weprovethat, ifT isabsolutelyCes`aroboundedona Banach(Hilbert)space,then Tn =o(n)( Tn =o(n1 2),respectively).Asa consequence,everyabsolutelyCes`aroboundedoperatoronareflexiveBanach spaceismeanergodic. YR 2020 FD 2020 LK http://riull.ull.es/xmlui/handle/915/35511 UL http://riull.ull.es/xmlui/handle/915/35511 LA en DS Repositorio institucional de la Universidad de La Laguna RD 27-nov-2024