Helmholtz and dispersive equations with variable coefficients on exterior domains

Federico Cacciafesta, Piero D'Ancona, Renato Luca'

We prove smoothing estimates in Morrey-Campanato spaces for a Helmholtz equation $$-Lu+zu=f,-Lu:={\nabla }^b(a(x){\nabla }^{b}u)-c(x)u,{\nabla }^b:=\nabla +ib(x)$$ with…