Energy density and packet formation in a vibrating cavity

Abstract

We give analytical expressions for the energy density of the massless scalar field excited from an arbitrary initial state (including vacuum) due to the non-stationary Casimir effect in an ideal one-dimensional cavity with vibrating walls, provided the frequency of vibrations is close to a multiple frequency of the fundamental unperturbed field mode. The formation of sharp packets is studied in detail. The influence of the initial state (vacuum, thermal and coherent) on the form of the packets is demonstrated.