The first billion years of a warm dark matter universe

摘要: We present results of cosmological N-body hydrodynamic chemistry simulations primordial structure growth and evolution in a scenario with warm dark matter (WDM) having mass 3 keV (thermal relic) compare model consisting standard cold (CDM). focus on the high-redshift universe ($z>6$), where formation process should better reflect (linear) differences terms power spectrum. find that early epochs can be exceptional probes dark-matter nature. Non-linear WDM spectra functions are up to 2 dex lower than CDM show spreads factor few persisting whole first Gyr. Runaway molecular cooling haloes severely inhibited because damping at large $k$ modes hence cosmic (population III II-I) star rate (SFR) is usually suppressed respect predictions. Luminous objects formed background very rare $z>10$, due sparser retarded mini-haloes during ages their lack fitted simple analytical formula depending only magnitude redshift. Future high-$z$ observations faint galaxies have potential discriminate between scenarios by means stellar density (SMD) specific SFR, as well. When compared effects alternative cosmologies (e.g. non-Gaussian or dark-energy models) high-order corrections $z$ streaming motions changes pristine IMF) ones caused definitely more dramatic.