SOLUTIONS OF THE TELEGRAPHERS EQUATION IN THE PRESENCE OF TRAPS - COMMENT

This comment corrects an explanation, given in a recent and interesting paper by Masoliver, Porra, and Weiss [Phys. Rev. A 45, 2222 (1992)], to account for one of the discontinuities of the probability density of the telegrapher process in the presence of a trap. The discontinuity is due to the trapping of the random walkers that would have undergone one reversal if there were no trap, instead of "reflections from the trapping point, i.e., from particles which reach the trap but reverse direction when they reach that point", quoting from the authors.