Bounds on sterile neutrino lifetime and mixing angle with active
  neutrinos by global 21 cm signal
  Sterile neutrinos can be a possible candidate for dark matter. Sterile
neutrinos are radiatively unstable and can inject photon energy into the
intergalactic medium (IGM). The injection of photon energy into IGM can modify
the temperature and ionization history of IGM gas during cosmic dawn.
Theoretical models based on the {\Lambda}CDM framework predict an absorption
profile in the 21 cm line during the cosmic dawn era. Recently, the Experiment
to Detect the Global Epoch of Reionization Signature (EDGES) collaboration
confirmed such an adsorption signal. Injection of energy into IGM can modify
the absorption amplitude in the 21 cm signal. Considering the 21 cm absorption
signal at cosmic dawn, we constrain the lifetime of sterile neutrinos and the
mixing angle of sterile neutrinos with active neutrinos. We also compare these
bounds with other astrophysical observational bounds.
