Improvement of a conserved current density versus adding a total derivative to a Lagrangian density

Abstract

who made a large variety of original contributions to diverse fields of theoretical and mathematical physics, and in particular to classical and quantum field theory. The discussions with him have always been quite pleasant and enlightening. By his humbleness, attentiveness, kindness and generosity he has been a great example and steady encouragement. His precious advice, fine mind, humor and reassuring presence are deeply missed.