2011/07/21 by Dorothee Frey, Frey, Dorothee
Mathematics · #Classical Analysis and ODEs (math.CA) #FOS: Mathematics #Functional Analysis (math.FA) #math.CA #math.FA
paper · pdf · doi:10.48550/arxiv.1107.4348
26 pages
arxiv created 2011/07/21 · arxiv updated 2011/07/22
Let X be a space of homogeneous type and let L be a sectorial operator with bounded holomorphic functional calculus on L2(X). We assume that the semigroup \e-tL\t>0 satisfies Davies-Gaffney estimates. In this paper, we introduce a new type of paraproduct operators that is constructed via certain approximations of the identity associated to L. We show various boundedness properties on Lp(X) and the recently developed Hardy and BMO spaces HpL(X) and BMOL(X). In generalization of standard paraproducts constructed via convolution operators, we show L2(X) off-diagonal estimates as a substitute for Calderón-Zygmund kernel estimates. As an application, we study differentiability properties of paraproducts in terms of fractional powers of the operator L. The results of this paper are fundamental for the proof of a T(1)-Theorem for operators beyond Calderón-Zygmund theory, which will be the subject of a forthcoming paper.