Reply by authors to discussion by Sven-Erick Hjelt

Dr. Hjelt’s discussion on our note has been read with interest. We agree that a technique involving separation of time and space variables is more direct for the specific problem being treated. This is particularly the case when we know the expected form of the final solution at the outset [i.e., his equation (1)]. Our analysis showed that the integral representation is fully equivalent to his exponential series solution. Therefore, there is no area of disagreement.