Cosmic neutrino background detection in large-neutrino-mass cosmologies

The cosmic neutrino background (CNB) is a definite prediction of the standard cosmological model and its direct discovery would represent milestone in cosmology physics. In this work, we consider capture relic neutrinos on tritium target as possible way to detect CNB, aimed for by PTOLEMY project. Crucial parameters measurement are absolute mass ${m}_{\ensuremath{\nu}}$ local number density ${n}_{\ensuremath{\nu}}^{\mathrm{loc}}$. Within $\mathrm{\ensuremath{\Lambda}}\mathrm{CDM}$ model, provides stringent upper limit sum masses $\ensuremath{\sum}{m}_{\ensuremath{\nu}}<0.12\text{ }\text{ }\mathrm{eV}$, with further improvements expected soon from galaxy surveys DESI EUCLID. This makes prospects CNB detection laboratory very difficult. context, set nonstandard models that allow large (${m}_{\ensuremath{\nu}}\ensuremath{\sim}1\text{ }\mathrm{eV}$), potentially reach KATRIN experiment or upcoming neutrinoless double-beta decay searches. We show could be much higher some these compared those $\mathrm{\ensuremath{\Lambda}}\mathrm{CDM}$, discuss potential such discriminate between scenarios. Moreover, provide simple rule estimate required values energy resolution, exposure, rate PTOLEMY-like cover certain region $({m}_{\ensuremath{\nu}},{n}_{\ensuremath{\nu}}^{\mathrm{loc}})$ parameter space. Alongside paper, publicly release code calculate sensitivity given model.