A multi-component SIMP model with $U(1)_X \rightarrow Z_2 \times Z_3$
  Multi-component dark matter scenarios are studied in the model with $U(1)_X$
dark gauge symmetry that is broken into its product subgroup $Z_2 \times Z_3$
\'{a} la Krauss-Wilczek mechanism. In this setup, there exist two types of dark
matter fields, $X$ and $Y$, distinguished by different $Z_2 \times Z_3$
charges. The real and imaginary parts of the $Z_2$-charged field, $X_R$ and
$X_I$, get different masses from the $U(1)_X$ symmetry breaking. The field $Y$,
which is another dark matter candidate due to the unbroken $Z_3$ symmetry,
belongs to the Strongly Interacting Massive Particle (SIMP)-type dark matter.
Both $X_I$ and $X_R$ may contribute to $Y$'s $3\rightarrow 2$ annihilation
processes, opening a new class of SIMP models with a local dark gauge symmetry.
Depending on the mass difference between $X_I$ and $X_R$, we have either
two-component or three-component dark matter scenarios. In particular two- or
three-component SIMP scenarios can be realised not only for small mass
difference between $X$ and $Y$, but also for large mass hierarchy between them,
which is a new and unique feature of the present model. We consider both
theoretical and experimental constraints, and present four case studies of the
multi-component dark matter scenarios.
