Asteroseismic constraints on asymmetric dark matter: Light particles with an effective spin-dependent coupling

So far, direct detection searches have come up empty handed in their quest for dark matter (DM). Meanwhile, asteroseismology arises as a complementary tool to study DM, as its accumulation in a star can enhance energy transport by providing a conduction mechanism, producing significant changes in the stellar structure during the course of the star's evolution. The stellar core, particularly affected by the presence of DM, can be investigated through precise asteroseismic diagnostics. We modeled three stars including DM energy transport: the Sun; a slightly less massive and much older star, KIC 7871531 (0.85 M-circle dot, 9.41 Gyr); and a more massive and younger one, KIC 8379927 (1.12 M-circle dot, 1.82 Gyr). We considered both the case of weakly interactive massive particles, albeit with a low annihilation, and the case of asymmetric DM for which the number of trapped particles in the star can be much greater. By analyzing these models with asteroseismic separation ratios weighted towards the core, we found indications limiting the effective spin-dependent DM-proton coupling for masses of a few GeV. This independent result is very close to the most recent and most stringent direct detection DM constraints.