k-Jet field approximations to geodesic deviation equations

Let M be a smooth manifold and S a semi-spray defined on a sub-bundle C of the tangent bundle TM. In this work, it is proved that the only non-trivial k-jet approximation to the exact geodesic deviation equation of S, linear on the deviation functions and invariant under an specific class of local coordinate transformations, is the Jacobi equation. However, if the linearity property on the dependence in the deviation functions is not imposed, then there are differential equations whose solutions admit k-jet approximations and are invariant under arbitrary coordinate transformations. As an example of higher-order geodesic deviation equations, we study the first- and second-order geodesic deviation equations for a Finsler spray.