Abstract. Let H be a selfadjoint operator and A a closed operator on a Hilbert space H. If A is H-(super)smooth in the sense of Kato-Yajima, wesmooth. This allows to include wave and Klein-Gordon equations in the abstract theory at the same level of generality as Schrödinger equations.We give a few applications and in particular, based on the resolvent estimates of Erdogan, Goldberg and Schlag [9], we prove Strichartz estimates for wave equations perturbed with large magnetic potentials on R n , n ≥ 3.