The existence of so-called radiation-free states in the transient motion of dislocations was investigated. By analyzing an edge dislocation which jumped from rest to a supersonic speed, it was found that the Mach fronts disappeared at a certain dislocation velocity; where the pole singularity in the complex plane was replaced by a removable one. However, there existed radiated stress waves which propagated at a different velocity. Due to the existence of radiated longitudinal waves, a putative force was required in order to maintain such a motion.

On “Radiation-Free” States in Transient Motion of Dislocations. X.Markenscoff: Applied Physics Letters, 2001, 78[4], 440-2