CPproperties of light neutrinos and double-βdecay in SO10

We assume that the Gell-Mann—Ramond—Slansky mechanism is responsible for giving mass to the neutrinos and discuss the $\mathrm{CP}$ eigenvalues of neutrinos that arise in a wide class of S${\mathrm{O}}_{10}$ models. We find that in such models, some of the light neutrinos have different $\mathrm{CP}$ eigenvalues than others. We also discuss the implications for the measurements on neutrinoless double-$\beta$ decay.