Short-baseline neutrino oscillations and(ββ)0νdecay in schemes with an inverted mass spectrum

We have considered short-baseline neutrino oscillations, ${}_{}{}^3{}_{}{}^{}\mathrm{H}$ $\beta$ decay, and ${\left(\beta \beta \right)}_{0\nu }$ decay in two schemes with an inverted mass spectrum and mixing of three and four massive neutrino fields. We have analyzed the results of the latest experiments on the search for oscillations of terrestrial neutrinos and we have discussed the compatibility of the LSND indication in favor of neutrino oscillations with the results of the other experiments. In the framework of the models under consideration, it is shown that the observation of ${\left(\beta \beta \right)}_{0\nu }$ decay could allow us to obtain information about the $\mathrm{CP}$ violation in the lepton sector.