The role of symmetry in the interpretation of quantum mechanics

Abstract: Despite the impressive amount of literature on the foundations of quantum mechanics, the relevance of symmetry in interpretation is not properly acknowledged. In fact, although it is usually said that quantum mechanics is invariant under the Galilean group, the invariance is usually not discussed in the case of the interpretation of the theory. This situation is particularly pressing for realist positions, which want to know how reality would be if quantum mechanics were true. From a realist perspective, it seems reasonable to require that an interpretation of quantum mechanics, to be admissible, preserves the same symmetries of the theory. In this paper we will take a realist standpoint in order to study what physical constraints the Galilean group imposes on interpretation, and we will extrapolate the conclusions drawn for quantum mechanics to the case of quantum field theory.