📝 SummarXiv

Abstract

Gravitational lensing is a powerful tool to probe compact astrophysical objects and the distribution of dark matter at large scales. As a counterpart of photons, lensed relativistic neutrinos could also be used to explore properties of curved spacetimes. In the present paper we consider neutrinos oscillations in the Ellis wormhole (WH) spacetime. We investigate the oscillations involving lensing effects with 2-flavor neutrinos under the weak-field approximation. In this case the flavor oscillation probabilities are sensitive to neutrino mass hierarchy, and the lightest neutrino mass. The influence of the Ellis WH on the coherence of neutrinos is also studied in the weak-field regime. We find no significant modification to the decoherence length from the lensing effect. To overcome the limit of the weak-field approximation where only small throats are considered for given geometrical parameters, we perform strict calculations to explore the throats effects on the 3-flavor neutrino oscillations. In the case of normal mass ordering, an interesting separation phenomenon in the oscillation curves appears in the special range of geometric parameter. In particular, we observe that CP violations in neutrino oscillations in the curved spacetime can be discriminated from the violation in the flat spacetime. Thus, in the strong-field regime, nontrivial spacetime information may be encoded in the CP violation of neutrinos.