Detecting the radiative decay of the cosmic neutrino background with line-intensity mapping

Understand

We study the possibility to use line-intensity mapping (LIM) to seek photons from the radiative decay of neutrinos in the cosmic neutrino background.

• The Standard Model prediction for the rate for these decays is extremely small, but it can be enhanced if new physics increases the neutrino electromagnetic moments.
• The decay photons will appear as an interloper of astrophysical spectral lines.
• We propose that the neutrino-decay line can be identified with anisotropies in LIM clustering and also with the voxel intensity distribution.