The Core-Cusp Problem Revisited: ULDM vs. CDM [CEA]

http://arxiv.org/abs/1908.02508


The core-cusp problem is often cited as a motivation for the exploration of dark matter models beyond standard CDM [cold dark matter]. One such alternative is ULDM [ultra-light dark matter]; particles exhibiting wavelike properties on kiloparsec scales. ULDM dynamics are governed by the Schodinger-Poisson equations, which have solitonic ground state solutions consisting of gravitationally-bound condensates with no internal kinetic energy. Astrophysically realistic ULDM halos would consist of larger NFW-like configurations with a possible solitonic core. We describe a parameterisation for the radial density profiles of ULDM halos that accounts for the environmental variability of the core-halo mass relation. We then compare the semi-analytic profiles of ULDM and CDM with astrophysical data, and find that a ULDM particle mass of 10^(-23) eV can yield a reasonably good fit to observed rotation data, particularly at small radii. This ULDM mass is in tension with other constraints but we note that this analysis ignores any contribution from baryonic feedback.

Read this paper on arXiv…

E. Kendall and R. Easther
Thu, 8 Aug 19
52/78

Comments: 15 pages