Conditional Linearizability Criteria for Scalar Fourth Order Semi-Linear Ordinary Differential Equations

Using geometric methods for linearizing systems of second order cubically semi-linear ordinary differential equations and third order quintically semi-linear ordinary differential equations, we extend to the fourth order by differentiating the third order equation. This yields criteria for linearizability of a class of fourth order semi-linear ordinary differential equations, which have not been discussed in the literature previously. It is shown that the procedure can be extended to higher order. Though the results for the higher orders are complicated, they are doable by algebraic computing. The standard Lie approach, as developed at present does not seem to be amenable to giving results that can be handled even by algebraic computing.