416 research outputs found
Partially Composite Dynamical Dark Matter
In this paper, we consider a novel realization of the Dynamical Dark Matter
(DDM) framework in which the ensemble of particles which collectively
constitute the dark matter are the composite states of a strongly-coupled
conformal field theory. Cosmological abundances for these states are then
generated through mixing with an additional, elementary state. As a result, the
physical fields of the DDM dark sector at low energies are partially composite
-- i.e., admixtures of elementary and composite states. Interestingly, we find
that the degree of compositeness exhibited by these states varies across the
DDM ensemble. We calculate the masses, lifetimes, and abundances of these
states -- along with the effective equation of state of the entire ensemble --
by considering the gravity dual of this scenario in which the ensemble
constituents are realized as the Kaluza-Klein states associated with a scalar
propagating within a slice of five-dimensional anti-de Sitter (AdS) space.
Surprisingly, we find that the warping of the AdS space gives rise to
parameter-space regions in which the decay widths of the dark-sector
constituents vary non-monotonically with their masses. We also find that there
exists a maximum degree of AdS warping for which a phenomenologically
consistent dark-sector ensemble can emerge. Our results therefore suggest the
existence of a potentially rich cosmology associated with partially composite
DDM.Comment: 25 pages, LaTeX, 6 figures, 1 tabl
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