Galileon-like vector fields

Understand

We construct simple Lagrangians of vector fields which involve second derivatives, but nevertheless lead to second order field equations.

• These vector fields are, therefore, analogs of generalized Galileons.
• Our construction is given first in Minkowski space, and then generalizied to include dynamical gravity.
• We present examples of backgrounds that are stable and ghost-free despite the absence of gauge invariance.