Abstract:
In this talk, we outline an algorithm for factoring a linear
homogeneous partial differential system whose coefficients are
rational functions in two independent variables x, y, and whose
solution space is finite-dimensional over the constant field.
In other words, the algorithm computes all left ideals containing
a given zero-dimensional left ideal in the ring of partial
differential operators Dx and Dy over the field of rational
functions in x and y.
Our approach is based on
1. a generalization of the associated equations technique
used in the factorization of linear ode's, and
2. a method for finding hyperexponential solutions of
zero-dimensional left ideals of differential operators.
We also introduce the notion of quotients, and discuss how to
represent all the solutions of a given system by the solutions
of its factors and quotients.
Cheriton School of Computer Science
University of Waterloo
200 University Avenue West
Waterloo, Ontario, Canada N2L 3G1
519 888 4567
| http://www.scg.uwaterloo.ca



