Speaker
Description
We study spherically symmetric, time-independent solutions of the Einstein field equations sourced by a complex scalar field charged under a $U_a(1)$ gauge field that is kinetically mixed with a second $U_b(1)$ gauge field. This scenario is motivated by the Scalar (Fuzzy) Field Dark Matter model (SFDM) charged under the massless Dark Photon (DP) interaction.We find compact, self-gravitating, regular solutions of the system and demonstrate that regularity at the spatial origin necessarily implies that both gauge fields are proportional up to an additive constant. This behavior persists in both the diagonalized and non-diagonalized cases of the kinetic mixing term, so the total mass $M$ and total Noether charge $Q$ versus radius curves are degenerate with those of the usual single charged boson star. Finally, we briefly discuss the consequences of current constraints on the parameters of milli-charged dark matter particles for this model.