Invariant characterization of scalar third‐order ODEs that admit the maximal point symmetry Lie algebra

摘要

> The Cartan equivalence method is used to deduce an invariant characterization of the scalar third‐order ordinary differential equation u ″ ′ = f ( x , u , u ′ , u ″ ) , which admits the maximal 7‐dimensional point symmetry Lie algebra. The method provides auxiliary functions that can be used to efficiently obtain the point transformation that does the reduction to the simplest linear equation ū ″ ′ = 0