Let M be a complete connected Riemannian manifold. Assuming that the Riemannian measure is doubling, we define Hardy spaces H of differential forms on M and give various characterizations of them,â€¦ (More)

We prove quadratic estimates for complex perturbations of Diractype operators, and thereby show that such operators have a bounded functional calculus. As an application we show that spectralâ€¦ (More)

Let X be a space of homogeneous type The aims of this paper are as follows i Assuming that T is a bounded linear operator on L X we give a su cient condition on the kernel of T so that T is of weakâ€¦ (More)

We consider second order elliptic divergence form systems with complex measurable coefficients A that are independent of the transversal coordinate, and prove that the set of A for which the boundaryâ€¦ (More)

We provide a direct proof of a quadratic estimate that plays a central role in the determination of domains of square roots of elliptic operators and, as shown more recently, in some boundary valueâ€¦ (More)

The in vitro-released 'excretory/secretory' (ES) and somatic antigens of the third stage (infective) larva of Anisakis simplex were characterised by radioiodination, immunoprecipitation, and sodiumâ€¦ (More)

Let L be an elliptic differential operator with bounded measurable coefficients, acting in Bochner spaces L p (R n ; X) of X-valued functions on R n. We characterize Kato's square root estimates âˆšâ€¦ (More)

p associated to a sectorial operator A on Lp for 1 < p < âˆž. Under the assumption that A is actually R-sectorial, we prove equivalences of the form Kâ€–xâ€–G â‰¤ â€–xâ€–F â‰¤ Kâ€–xâ€–G for suitable functions F,G. Weâ€¦ (More)