CP violations in neutrino oscillations modulated by singular and non-singular gravities

Flavor oscillations in curved space-time provide a novel channel to explore the unknown parameters of neutrinos. In this work, the gravity-modulated CP violations (CPVs) in neutrino oscillations were investigated under the Reissner-Nordstrom, Hayward, and Simpson-Visser metric. The interplay among the CPV, the properties of neutrinos, and the space-time is illustrated with analytical and numerical methods. The morphologies of the flavor-oscillation curves show that the information on the mass-ordering, the absolute mass, and the gravitational parameters could be encoded into the amplitudes and periods of the CPVs. Hence, the characteristic of the space-time background may be identified through its modulation effects on the CPV, such as amplification, damping on the amplitudes.