Electromagnetically Interacting Massive Spin-2 Field: Intrinsic Cutoff and Pathologies in External Fields

By employing the Stueckelberg formalism, we argue that the theory of massive spin-2 field coupled to electromagnetism in flat space must have an intrinsic, model independent, finite UV cutoff. We show how the very existence of a cutoff has connection to other pathologies of the system, such as superluminal propagation. We comment on the generalization of the results to arbitrary spin, and to gravitational interaction.