A Comparison of Two Methods to Calculate Conservation Laws of PDE systems

Thomas Wolf
Queen Mary and Westfield College, London
email:  tw@maths.qmw.ac.uk

The methods of calculating conservation laws either directly or through the
calculation of their characteristic function are compared concerning the the
invariance of the result they provide and their complexity.  Two corresponding
computer algebra programs are compared concerning the range of problems they
are applicable to and their efficiency.  Applications are given including a
conservation law of an evolutionary system of equations known from plasma
physics with a conserved density depending explicitly on the independent
variables.