XTE J1814-338 as a strange star admixed with bosonic dark matter

We show that the compact star XTE J1814-338 can be explained as a strange star admixed with self-interacting bosonic dark matter (BDM), provided the dark matter fraction exceeds approximately 70\%. This interpretation leads to a robust constraint on the BDM particle mass: $m_\chi \lesssim 307(\lambda/\pi)^{1/4}$ MeV ($\lambda$ is the dimensionless coupling constant of the BDM). The result is independent of formation scenario and microphysical details and is falsifiable by future NICER and LIGO/Virgo observations.