Asteroseismological constraints on--and hints of--dark matter interactions

TL;DR

This paper explores how dark matter interactions can influence stellar structures, using asteroseismology to set constraints and find potential evidence for dark matter-electron interactions, especially in stars similar to the Sun.

Contribution

It introduces a novel method of using asteroseismology to constrain dark matter interactions and provides new limits and potential evidence for dark matter-electron interactions.

Findings

Limits on spin-dependent dark matter-nucleon interactions.

Preference for dark matter-electron interactions at certain masses and cross sections.

Tension with Earth-based detection limits.

Abstract

If dark matter interacts with nuclei or electrons, then elastic collisions with constituents of stars will cause some of the galactic dark matter to fall below the escape velocity and become gravitationally bound. For asymmetric dark matter (which does not self-annihilate), the large accumulated population of dark matter can act as an additional source of heat transport, altering stellar structure and evolution. These effects can be probed by the use of asteroseismology. Here, we demonstrate this effect via numerical simulations. We use Monte Carlo-calibrated heat transport calculations, with a focus on the erasure of the convective core in stars that are slightly more massive than the Sun. We find limits on spin-dependent dark matter-nucleon and dark matter-electron interactions using asteroseismological data from a nearby sub-giant star. More tantalizingly, we find a $\gtrsim 4 \sigma$ preference for dark matter-electron interactions for dark matter masses $\lesssim 3.5$ GeV and cross sections $\sigma_{\chi-e} \sim 10^{-34.5}$ cm$^2$, albeit in strong tension with limits from Earth-based direct detection experiments.