Key points are not available for this paper at this time.
In the canonical type-I seesaw mechanism for neutrino masses, a residual symmetry known as lepton parity: (-1) L, remains preserved. Introducing a Majorana fermion S with even lepton parity renders it naturally stable, making it a viable dark matter (DM) candidate. The addition of a lepton parity odd singlet scalar σ allows for the coupling N S σ, where N is the right-handed neutrino. If S is not thermalized, then DM relic can be produced in two distinct ways: (i) for reheating temperature, T ₑ₇>m₍, dominantly through the decay of N (N Sσ), and (ii) for T ₄ₖ
Ma et al. (Thu,) studied this question.