Fidelity decay measures the memory loss rate of the perturbed vs given orbits.

Reversibility and forward errors are asymptotically the same for linear maps.

Numerical equivalence is found for regular and chaotic three body orbits.

Fidelity decays exponentially for regular noisy orbits as proved for integrable maps.

Fidelity has a plateau before decay for noisy chaotic orbits as proved for baker’s map.