Noninvariant Boundary Conditions

It is generally believed that in order to solve initial and boundary value problems using Lie symmetry methods, the boundary and initial conditions need to be left invariant by the infinitesimal symmetry generator which admits the invariant solution. In this article we give less restrictive conditions on the imposed initial and boundary values in order that they be recoverable with a particular symmetry generator.

Keywords:

• Classical Symmetries
• Initial Value Problems
• Boundary Value Problems
• Ams Subject Classifications: 35a30
• 58j70
• 76m60