Tim Maudlin (New York University): "The Universal and the Local in Quantum Theory". Listen to the talk here.

Abstract:  Any clear ontological account of quantum theory must postulate that systems have a quantum state. That state, represented by the wave function of the system, is not what John Bell called a “local beable”. Since experience presents us with a world of objects localized in space and time, Bell also insisted that any clear physical theory must contain some local beables. Bell counseled us to push these two pieces of ontology in different directions: the local beables should exist at microscopic scale and the quantum state should, ultimately, only exist fundamentally at the universal scale. That is, the only quantum state that fundamentally exists is the quantum state of the entire universe. This paper illustrates the challenges that such a picture presents, and how the challenges are solved in the “pilot wave” approach.