Anomalous c-axis transport in layered metals

Transport in metals with strongly anisotropic single-particle spectrum is studied. Coherent band transport in all directions, described by the standard Boltzmann equation, is shown to withstand both elastic and inelastic scattering as long as $E_F\tau \gg 1$. A model of phonon-assisted tunneling via resonant states located in between the layers is suggested to explain a non-monotonic temperature dependence of the c-axis resistivity observed in experiments.