Symbolic Computation Group
David R. Cheriton School of Computer Science


Friday, September 12, 2003, at U. of Waterloo.
Abstract:
If a *given* nonlinear differential equation (DE) or system of DEs is
to be investigated wrt. special properties, like infinitesimal
symmetries, then the resulting conditions (e.g. for the generators of
these symmetries) are linear. If, on the other hand, one wants to
*find* PDEs which obey higher order symmetries (as a prerequisite for
being integrable) then one searches for 2 things at once: DEs and
symmetries and the resulting conditions become nonlinear. In the
simplest case these are bilinear algebraic systems but they can
become large: >1000 equations for >200 unknowns.

Last modified on Sunday, 04 November 2012, at 15:42 hours.