8517020151129072906.0doi10.5565/PUBLMAT_56112_06driverartpubuabnorediartpubuaboai:ddd.uab.cat:85170articleid02141493v56n1p147engCruz-Uribe, DavidSharp norm inequalities for commutators of classical operatorsWe prove several sharp weighted norm inequalities for commutators of classical operators in harmonic analysis. We found suffcient Ap-bump conditions on pairs of weights (u; v) such that [b; T], b 2 BMO and T a singular integral operator (such as the Hilbert or Riesz transforms), maps Lp(v) into Lp(u). Because of the added degree of singularity, the commutators require a \double log bump" as opposed to that of singular integrals, which only require single log bumps. For the fractional integral operator I we nd the sharp one-weight bound on [b; I ], b 2 BMO, in terms of the Ap;q constant of the weight. We also prove sharp two-weight bounds for [b; I ] analogous to those of singular integrals. We prove two-weight weak type inequalities for [b; T] and [b; I ] for pairs of factored weights. Finally we construct several examples showing our bounds are sharp.info:eu-repo/semantics/openAccessTots els drets reservatshttp://www.europeana.eu/rights/rr-f/Anglès.recercaCommutatorsTwo-weight inequalitiesSharp weighted boundsinfo:eu-repo/semantics/articleinfo:eu-repo/semantics/publishedVersionSFOMoen, KabeVol. 56, Núm. 1 ( 2012), p. 147-190Publicacions matemàtiques0214-149344556491http://ddd.uab.cat/pub/pubmat/02141493v56n1/pubmat_a2012v56n1p147.pdf014719015602141493v56n12012ARTPUBUABPUBMATfile0MD5f78bf3576ff561a52536c72dd58c94ce556491bytestream1.5filepathpub/pubmat/02141493v56n1/pubmat_a2012v56n1p147.pdfdisk