** Next:** General Solutions to the
** Up:** The Homogeneous Helmholtz Equation
** Previous:** Plane Wave Expansion
** Contents**

For convenience, we **define** the following:

These are the basic solutions to the HHE that are also eigenfunctions
of
and
. Clearly there is an **implicit** label of
(or
) for these solutions. A general solution (on a suitable
domain) can be constructed out of a linear combination of any two of
them.

Robert G. Brown
2017-07-11