Indirect detection of boosted light scalar dark matter

We explore the possibilities of detecting MeV-scale boosted dark matter (DM) via astrophysical observations. Given a particular model framework, using gamma-ray data from $\mathtt{\text{COMPTEL}}$ and $\mathtt{\text{EGRET}}$, as well as neutrino constraints from the $\mathtt{\text{Super-Kamiokande}}$, $\mathtt{\text{Hyper-Kamiokande}}$, $\mathtt{\text{JUNO}}$, diffuse supernova neutrino background ($\mathtt{\text{DSNB}}$), and atmospheric neutrino observations, we find that boosted light scalar DM could be probed within the mass range of $\sim 20\text{\hspace{0.17em}⁣}-\text{\hspace{0.17em}⁣}80$ MeV, satisfying the Planck observed relic abundance. Our study shows, indirect search can play a key role in the detection of MeV-scale boosted DM, which are otherwise beyond the reach of usual collider or DM scattering experiments.