mango-osc: MANGO — A Neutrino Gradient Oscillator

MANGO (A Neutrino Gradient Oscillator) is a neutrino oscillation calculator written in JAX, differentiable end-to-end with respect to every input — not only the oscillation parameters, but the propagation geometry and the matter densities of individual Earth shells, neither of which appears as a parameter of an analytic probability formula.

It covers vacuum, constant-density, layered-PREM, arbitrary-profile and adiabatic solar propagation, together with non-standard interactions, 3+N sterile states, decoherence and non-unitary mixing, through four cross-checked unitary backends and an adaptive ODE integrator. Because the gradient does not stop at the probability, it composes downstream through detector response, event weighting and binning into a likelihood or Fisher information.

This release is the version from which the numbers in the accompanying paper are computed.