Solving polynomials with ordinary differential equations

Armengol Gasull (1) , Hector Giacomini (2)

1 UAB - Departament de Matemàtiques [Barcelona]
2 IDP - Institut Denis Poisson

In this work we consider a given root of a family of n-degree polynomials as a one-variable function that depends only on the independent term. Then we prove that this function satisfies several ordinary differential equations (ODE). More concretely, it satisfies several simple separated variables ODE, a first order generalized Abel ODE of degree n-1 and an (n-1)-th order linear ODE. Although some of our results are not new, our approach is simple and self-contained. For n=2, 3 and 4 we recover, from these ODE, the classical formulas for solving these polynomials.

Mots clés: Polynomial equation; Ordinary differential equation; Abel equations; Elliptic and hyperelliptic integrals

Domaines: Analyse classique [math.CA]

Armengol Gasull, Hector Giacomini. Solving polynomials with ordinary differential equations. 2020. ⟨hal-02879497⟩