Phenomenology of wavelike vector dark matter nonminimally coupled to gravity

Abstract

We study three astrophysical/cosmological consequences of nonminimal couplings to gravity in wavelike vector dark matter. In the nonrelativistic limit, the nonminimal coupling with the lowest mass dimension leads to effective self-interactions that affect the mass-radius relation of vector solitons, growth of linear perturbations during structure formation, and the speed of gravitational waves (GWs). Based on the success of cold dark matter on large-scale perturbations and the current limits on GW speed, we constrain the dark matter mass and nonminimal coupling strength to be within the range $|{\xi }_1|/m^2\ll 10^{50}\mathrm{e}{\mathrm{V}}^{-2}$ and $-3\times 10^{46}\mathrm{e}{\mathrm{V}}^{-2}\lesssim {\xi }_2/m^2\lesssim 8\times 10^{48}\mathrm{e}{\mathrm{V}}^{-2}$.

Comments: 13 pages + appendices, 2 figures