Resonant SIMP dark matter
  We consider a resonant SIMP dark matter in models with two singlet complex
scalar fields charged under a local dark $U(1)_D$. After the $U(1)_D$ is broken
down to a $Z_5$ discrete subgroup, the lighter scalar field becomes a SIMP dark
matter which has the enhanced $3\rightarrow 2$ annihilation cross section near
the resonance of the heavier scalar field. Bounds on the SIMP self-scattering
cross section and the relic density can be fulfilled at the same time for
perturbative couplings of SIMP. A small gauge kinetic mixing between the SM
hypercharge and dark gauge bosons can be used to make SIMP dark matter in
kinetic equilibrium with the SM during freeze-out.
