TITLE:
Simulations and Measurements of Warm Dark Matter Free-Streaming and Mass
AUTHORS:
Bruce Hoeneisen
KEYWORDS:
Dark Matter Mass, Warm Dark Matter Free-Streaming, Galaxy Mass Distribution, Spiral Galaxy Adiabatic Invariant
JOURNAL NAME:
International Journal of Astronomy and Astrophysics,
Vol.9 No.4,
December
11,
2019
ABSTRACT: 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 kfs of linear density perturbations. The challenge is to measure kfs. This study focuses on “smoothing lengths” π/kfs 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 masMfs, 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 kfs, and the mass mh of dark matter particles, based on the redshift of first galaxies, galaxy mass distributions, and rotation curves of spiral galaxies.