Does Non-Relativistic Quantum Theory Exist?

Tim Maudlin, Ph.D. Professor
New York University, USA

Many conceptual investigations into the possible ways to interpret the quantum formalism begin with the examination of the non-relativistic theory. For many purposes, this appears to be a good strategy. For example, if one is interested in how one could solve the measurement problem, there are non-relativistic theories that illustrate the various approaches, such as Bohmian mechanics, GRW, and Many Worlds. Having understood the non-relativistic case, one then asks how the basic form of the solution might be extended to the relativistic domain. This same strategy can be attempted when asking about the ontological status of the wavefunction. Questions about whether and how the mathematical object represents a physical reality can be asked in the non-relativistic setting, and the answers there used to inform investigation into the relativistic setting. I will suggest that this sort of approach may be seriously misleading, and that, in a particular sense, there is no non-relativistic version of quantum theory.