  The seed of dark matter can be generated from light spectator fields during
inflation through a similar mechanism that the seed of observed large scale
structures are produced from the inflaton field. The accumulated energy density
of the corresponding excited modes, which is subdominant during inflation,
dominates energy density of the universe later around the time of matter and
radiation equality and plays the role of dark matter. For spin-2 spectator
fields, Higuchi bound may seem to prevent excitation of such light modes since
deviation of the inflationary background from the exact de Sitter spacetime is
very small. However, sizable interactions with the inflaton field breaks (part
of) isometries of the de Sitter space in the inflationary background and
relaxes the Higuchi bound. Looking for this possibility in the context of
effective field theory of inflation, we suggest a dark matter model consisting
of spin-2 particles that produce during inflation.
