Abstract:
We construct the effective field theory for a single massive higher-spin particle in flat spacetime. Positivity bounds of the S-matrix force the cutoff of the theory
to be well below the naive strong-coupling scale, forbid any potential and make
therefore higher-derivative operators important even at low energy. As interesting
application, we discuss in detail the massive spin-3 theory and show that an extended
Galileon-like symmetry of the longitudinal modes, even with spin, emerges
at high energy.
