First integrals of nonlinear differential equations from nonlocal constants

Abstract

A new method to find first integrals of nonlinear differential equations in Jacobi-type form is presented. The basic idea of our approach is to use one-parameter perturbed motions to find well-conceived nonlocal constants that are conserved along solutions. By means of such nonlocal framework we derive a set of theorems that we apply to look for the first integrals of some relevant cases, where moreover a solution is obtained. Applications also include some equations of the Painlev´e–Gambier classification.

Keywords

• first integrals
• nonlinear odes
• non local costants