# Neutrino oscillations in extended theories of gravity

## TL;DR

This paper investigates how extended theories of gravity influence neutrino oscillations, revealing that neutrino phases are sensitive to violations of the strong equivalence principle and offering a way to constrain gravity models.

## Contribution

It provides a covariant framework for neutrino oscillations in extended gravity theories, analyzing the impact of curvature invariants on neutrino phases in vacuum and matter.

## Key findings

- Neutrino phases are affected by violations of the strong equivalence principle.
- Extended gravity models alter neutrino oscillation parameters.
- Potential to set new bounds on gravity model parameters.

## Abstract

We study neutrino oscillations within the framework of extended theories of gravity. Based on the covariant reformulation of Pontecorvo formalism, we evaluate the oscillation probability of neutrinos propagating in static spacetimes described by gravitational actions quadratic in the curvature invariants. Calculations are carried out in the two-flavor approximation, for oscillations both in vacuum and matter. It is shown that the neutrino phase is sensitive to the violation of the strong equivalence principle. By way of illustration, we specialize our analysis to various extended models of gravity in order both to quantify such a violation and to understand how the characteristic free parameters of these models affect the neutrino phase. The possibility to fix new bounds on these parameters and to constrain extended theories of gravity is finally discussed.