Comment on "Probing the Dark Matter-Electron Interactions via Hydrogen-Atmosphere Pulsating White Dwarfs''

Abstract

In Phys. Rev. D 98, 103023 (2018), a novel scenario was proposed to probe the interactions between dark matter (DM) particles and electrons, via hydrogen-atmosphere pulsating white dwarfs (DAVs) in globular clusters. The estimation showed that the scenario could hopefully test the parameter space: $5\mathrm{GeV}\le m_{\chi }\le 10^4\mathrm{GeV}$ and ${\sigma }_{\chi ,e}\ge 10^{-40}{\mathrm{cm}}^2$, where $m_{\chi }$ is the DM particle's mass and ${\sigma }_{\chi ,e}$ is the elastic scattering cross section between DM and electron. In this comment, we have determined the exact lower limit of the testable DM particle mass $\sim 1.38-1.58\mathrm{GeV}$, which depends on ${\sigma }_{\chi ,e}$. This gives us a credible lower limit of the testable DM particle mass in above scenario, and provide a clear upper limit of the DM particle mass which we should consider in future research.

2 pages, 1 figure