On a Symmetry Argument for the Guidance Equation in Bohmian Mechanics

Abstract

Bohmian mechanics faces an underdetermination problem: when it comes to solving the measurement problem, alternatives to the Bohmian guidance equation work just as well as the official guidance equation. Dürr, Goldstein, and Zanghì have argued that of the candidate guidance equations, the official guidance equation is the simplest Galilean‐invariant candidate. This symmetry argument—if it worked—would solve the underdetermination problem. But the argument does not work. It fails because it rests on assumptions about how Galilean transformations (especially boosts) act on the wavefunction that are (in this context) unwarranted. My discussion has larger morals about the physical significance of certain mathematical results (like, for example, Wigner’s theorem) in non‐orthodox interpretations of quantum mechanics.