The memory effect in impulsive plane waves: comments, corrections, clarifications

Understand

Recently the 'memory effect' has been studied in plane gravitational waves and, in particular, in impulsive plane waves.

• Based on an analysis of the particle motion (mainly in Baldwin-Jeffery-Rosen coordinates) a 'velocity memory effect' is claimed to be found in [P.-M.
• Zhang, C.
• Duval, and P.