Author(s)

Bruce Hoeneisen

Universidad San Francisco de Quito, Quito, Ecuador.

We compare simulated galaxy distributions in the cold ΛCDM and warm ΛWDM dark matter models. The ΛWDM model adds one parameter to the ΛCDM model, namely the cut-off wavenumber k_fs of linear density perturbations. The challenge is to measure k_fs. This study focuses on “smoothing lengths” π/k_fs in the range from 12 Mpc to 1 Mpc. The simulations reveal two distinct galaxy populations at any given redshift z: hierarchical galaxies that form bottom up starting at the transition mas M_fs, and stripped down galaxies that lose mass to neighboring galaxies during their formation, are near larger galaxies, often have filamentary distributions, and seldom fill voids. We compare simulations with observations, and present four independent measurements of k_fs, and the mass m_h of dark matter particles, based on the redshift of first galaxies, galaxy mass distributions, and rotation curves of spiral galaxies.

Dark Matter Mass, Warm Dark Matter Free-Streaming, Galaxy Mass Distribution, Spiral Galaxy Adiabatic Invariant

Hoeneisen, B. (2019) Simulations and Measurements of Warm Dark Matter Free-Streaming and Mass. International Journal of Astronomy and Astrophysics, 9, 368-392. doi: 10.4236/ijaa.2019.94026.