Zeta functions of dynamically tame Liouville domains

We define a dynamical zeta function for nondegenerate Liouville domains, in terms of Reeb dynamics on the boundary. We use filtered equivariant symplectic homology to (i) extend the definition of the zeta function to a more general class of "dynamically tame" Liouville domains, and (ii) show that the zeta function of a dynamically tame Liouville domain is invariant under exact symplectomorphism of the interior. As an application, we find examples of open domains in R^4, arbitrarily close to a ball, which are not symplectomorphic to open star-shaped toric domains.