Constraining dark matter interactions mediated by a light scalar with white dwarfs

Observations of white dwarfs in dark matter-rich environments can provide strong limits on the strength of dark matter interactions. Here we apply the recently improved formalism of the dark matter capture rate in white dwarfs to a general model in which dark matter interacts with the white dwarf ion components via a light scalar mediator. We compute the dark matter capture rate in the optically thin limit in a cold white dwarf from the globular cluster Messier. We then estimate the threshold cross section, which significantly varies as a function of the light scalar mediator mass mo in the range of 0.05mx < mo < mx , becomes constant when mo > mx. We also show that the bounds obtained from the dark matter capture in a white dwarf from the globular cluster Messier 4 are complementary to direct detection experiments and particularly strong in the sub-GeV regime.

Automated summary

Observations of white dwarfs in dark matter-rich environments can provide strong limits on the strength of dark matter interactions. This study applies an improved formalism of dark matter capture rate in white dwarfs to a general model involving light scalar mediator interaction. The findings show that the bounds obtained from dark matter capture in white dwarfs are complementary to direct detection experiments and particularly strong in the sub-GeV regime.