Generalized Proca action for an Abelian vector field

We revisit the most general theory for a massive vector field with derivative self-interactions, extending previous works on the subject to account for terms having trivial total derivative interactions for the longitudinal mode. In the flat spacetime (Minkowski) case, we obtain all the possible terms containing products of up to five first-order derivatives of the vector field, and provide a conjecture about higher-order terms. Rendering the metric dynamical, we covariantize the results and add all possible terms implying curvature.
Comment: LaTeX file, 15 pages, no figures. v2: some typos have been fixed. A couple of references added. Version to be published in Journal of Cosmology and Astroparticle Physics