Speaker
Description
In multi-component dark matter scenarios, dynamics of a
sub-component dark matter has been often ignored. In this talk, I will be pointing
out the hidden roles of a sub-component dark matter in the scenarios where the
dominant relics interact with the Standard Model sector only indirectly through the
sub-component. Distinctive cosmological dynamics of a sub-component dark
matter will be discussed. The thermal evolution of the sub-component is
significantly affected by the sizable self-scattering and the required annihilation
cross section of the sub-component sharply increases as we consider a smaller
relative abundance fraction among the dark-matter species. Therefore, contrary to
a naive expectation, it can be easier to detect the sub-component with smaller
abundance fractions in direct/indirect-detection experiments and cosmological
observations.
