Schedule Feb 17, 2012
Structure Formation in Cosmological Models with Nonthermally Produced Warm Dark Matter and with Decaying Charged Massive Particles
Ayuki Kamada (Univ. of Tokyo)

We study the formation of nonlinear structure in Lambda Warm Dark Matter (WDM) cosmology and Charged Massive Particle (CHAMP) cosmology using large cosmological N-body simulations. We consider three WDM models and one CHAMP model. In the three WDM models, DM particles are produced in different ways; one kinetically decoupling from thermal bath, the other nonthermally decaying from heavy bosons in thermal bath and yet another decaying from heavy particle (e.g. WIMPs) decoupled from thermal bath. When they have the same Jeans length at matter-radiation equality, the resulting power spectra are very similar except for difference in damping tale of power spectra.

CHAMPs with life time about one year also show cut-off at subgalactic scales in power spectra through its acoustic oscillation with baryons.

We perform large cosmological N-body simulations to study the matter distribution in these models. We compare subgalactic structure of these models with that of CDM and discuss about how they resolve the so-called "Missing-Satellite Problem".


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