ETD

Archivio digitale delle tesi discusse presso l'Università di Pisa

Tesi etd-09022016-165739


Tipo di tesi
Tesi di laurea magistrale
Autore
ZUCCA, FABRIZIO
URN
etd-09022016-165739
Titolo
A computer algebra approach to rational general solutions of algebraic ordinary differential equations
Dipartimento
MATEMATICA
Corso di studi
MATEMATICA
Relatori
relatore Prof. Winkler, Franz
relatore Dott. Caboara, Massimo
Parole chiave
  • Rational Parametrization
  • Differential Algebra
  • Rational Solution
  • AODE
  • Rational Curves
  • Rational Surface
Data inizio appello
14/10/2016
Consultabilità
Completa
Riassunto
In this thesis, I approach to algebraic ODEs from Differential Algebra's point of view. I look for rational solutions of AODE, I present an algebro-geometric method to decide the existence of rational solutions of a first-order algebraic ODE and if they exist an algorithm to compute them. This method depends heavily on rational parametrizations, in particular for autonomous equations on the parametrization of algebraic curves, and for non-autonomous equations on the parametrization of algebraic surfaces. In the last case, I prove the correspondence between rational solutions of a parametrizable algebraic ODE and rational solutions of a first-order linear autonomous differential system of two equations in two variables. I provide an algorithm to compute rational solutions of such system based on its invariant algebraic curves. I also study a group of affine transformations which preserves the rational solvability, in order to reduce, when possible, an algebraic ODE to an easier one. Moreover I present the results of the implementation of all these algorithms in two computer algebra system: CoCoA and Singular.
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