Galoisian and numerical approach of three dimensional linear differential systems with skew symmetric matrices defined in a non- constant differential field

Abstract

This work contrasts numerical methods with algebraic methods. These methods are applied to solve a three dimensional linear differential system with skew symmetric matrices defined in a non- constant differential field. Algorithms and methods of Differential Galois Theory, are used to provide an algebraic solution, while numerical methods, in particular, methods from Runge - Kutta family, are applied to the same system. Finally, the absolute and relative errors between Liouvillians solution are calculated comparing the solutions obtained by means of algebraic methods and by means of numerical methods.

Este trabajo contrasta métodos numéricos con métodos algebraicos aplicados ambos a la resolución de un sistema de ecuaciones diferenciales lineales 3-dimensionales con matrices antisimétricas definidas en un cuerpo diferencial no constante. Al mismo sistema se aplican métodos y algorítmos propios de la Teoría de Galois Diferencial, lo que permite resolverlo algebraicamente y métodos numéricos, en particular métodos de la familia de Runge - Kutta. Por último, se calculan los errores absolutos y relativos entre las soluciones Liouvillianas, obtenidas mediante la resolución algebraica y las soluciones obtenidas aplicando métodos numéricos.