CosmologicalN-body simulations with generic hot dark matter

Discreteness Effects in Simulations of Hot/Warm Dark Matter

In Hot or Warm Dark Matter universes the density fluctuations at early times contain very little power below a characteristic wavelength related inversely to the particle mass. We study how discreteness noise influences the growth of nonlinear structures smaller than this coherence scale in N -body simulations of cosmic structure formation. It has been known for 20 years that HDM simulations in...

The Hot Dark Matter

There is a puzzling contradiction: direct observations favor a low-mass-density universe (0.2 ≤ Ωm ≤ 0.6), but the only model which fits universe structure over more than three orders of magnitude in distance scale has a mix of hot (neutrino) and cold dark matter providing a critical density universe. Models of an open universe (low Ωm) or one adding a cosmological constant (Λ) to provide a cri...

Hot Dark Matter

Cosmic strings with interacting hot dark matter

We compute the linear power spectrum of cosmic string sedeed fluctuations in the context of neutrinos with a strong self-interaction and show that it is very similar to that obtained in the context of ‘normal’ neutrinos. We compare our results with observational data and show that for any value of the cosmological parameters h and Ω0 the interacting hot dark matter power spectrum requires a lar...

Hidden Hot Dark Matter as Cold Dark Matter

We show that hidden hot dark matter, hidden-sector dark matter with interactions that decouple when it is relativistic, is a viable dark matter candidate provided it has never been in thermal equilibrium with the particles of the standard model. This hidden hot dark matter may reheat to a lower temperature and number density than the visible Universe and thus account, simply with its thermal ab...