4 for Dirac) and $K_{n}$ are modified Bessel functions of the second kind. This potential is reliable since the contributions from higher thresholds are exponentially suppressed compared to the neutrino contributions by factors of order $e^{-m/m_\nu}$. It has local minima in AdS if neutrinos are Majorana [@Nima]. This is due to the fact that the lightest neutrino contributes positively to the potential with 2 degrees of freedom, which is not enough to compensate for the 4 bosonic degrees of freedom contributing negatively from photon and graviton. However, if the lightest neutrino is Dirac (and it is lighter than the c.c. scale $\Lambda_4^{1/4}$) it contributes positively with 4 (instead of 2) degrees of freedom, which is enough to compensate for the 4 massless degrees of freedom of the photon and the graviton. The potential is then monotonously decreasing for large R and no AdS minima develops. This fact has been used to obtain bounds on the lightest neutrino mass and the 4D cosmological constant [@IMV1] by imposing the condition suggested in [@OV] that AdS non-SUSY vacua are in the swampland (see also [@2toro; @Gonzalo; @Hamada]). One obtains four very relevant implications for the SM [@IMV1]:

-   The lightest neutrino is Dirac.

