Galactic rotation curves versus ultralight dark matter: A systematic comparison with SPARC data

TL;DR

This study uses galaxy rotation data to constrain ultralight dark matter models, finding that ULDM likely does not make up all dark matter within certain particle mass ranges, especially under specific soliton-halo relations.

Contribution

It provides observational constraints on ULDM soliton cores in galaxies, challenging some simulation-based relations and limiting ULDM's contribution to dark matter.

Findings

ULDM is disfavored as 100% of dark matter in certain mass ranges.

Constraints extend to ULDM fractions as low as 30%.

Results challenge some theoretical soliton-halo relations.

Abstract

We look for and place observational constraints on the imprint of ultralight dark matter (ULDM) soliton cores in rotation-dominated galaxies. Extending previous analyses, we find a conservative constraint which disfavors the soliton-host halo relation found in some numerical simulations over a broad range in the ULDM particle mass $m$. Combining the observational constraints with theoretical arguments for the efficiency of soliton formation via gravitational dynamical relaxation, and assuming that the soliton-halo relation is correct, our results disfavor ULDM from comprising 100\% of the total cosmological dark matter in the range $10^{-24}~{\rm eV}\lesssim m\lesssim10^{-20}~{\rm eV}$. The constraints probe the ULDM fraction down to $f\lesssim0.3$ of the total dark matter.