Published online by Cambridge University Press: 24 October 2008
Let
be a system of differential equations in which X1, … Xn are analytic functions independent of t, expansible in convergent series of powers of x1, … xn. Suppose further that not all the functions X1, … Xn vanish when x1 = … = xn = 0. It will be shown in §§ 1–3 that these equations possess (n — 1) independent integrals independent of t, expansible in convergent series of powers of x1, … xn; i.e. functions
such that
identically. In § 4 it is shown how the series for ϕ1,…ϕn−1 may be most directly constructed, and in § 5 is briefly considered the corresponding problem when the origin is a singular point of the equations, i.e. when the expansions of X1,…Xn all begin with terms of the first or higher degrees.
* See, for example, Painlevé, , Léçons sur la théorie analytique des équations différentielles, p. 394.Google Scholar
* “On Integrals developable about a Singular Point of a Hamiltonian System of Differential Equations,” p. 325, below.