Voyage to Alpha Centauri: Entanglement degradation of cavity modes due to motion

We propose a scheme to investigate whether nonuniform motion degrades entanglement of a relativistic quantum field that is localized both in space and in time. For a Dirichlet scalar field in a cavity in Minkowski space, in small but freely adjustable acceleration of finite but arbitrarily long duration, degradation of observable magnitude occurs for massless transverse quanta of optical wavelength at Earth gravity acceleration and for kaon mass quanta already at microgravity acceleration. We outline a space-based experiment for observing the effect and its gravitational counterpart.