We prove that the linearized Riesz transforms and the imaginary powers of the Laplacian are H<sup>1</sup>-bounded on complete Riemannian manifolds satisfying the doubling property and the Poincaré inequality, where H<sup>1</sup> denotes the Hardy space on M.
Steve HofmannMarius MitreaSylvie Monniaux
Giancarlo MauceriStefano MedaMaria Vallarino