Adrian Kent,
University of Cambridge, UK

Title and Abstract:

One World Versus Many
There is a compelling intellectual case for exploring whether purely unitary quantum theory defines a sensible and scientifically adequate theory, as Everett originally proposed. Many different and incompatible attempts to define a coherent Everettian quantum theory have been made over the past fifty years, suggesting this is a problem about which humans are excellent at forming strong intuitions but very bad at forming persuasive arguments.

In this talk I review recent work in this area. I argue that considerable light is shed on the problem once one realizes that many-worlds theories are just that -- novel and distinct scientific theories, not reinterpretations of standard quantum theory. This forces us to reconsider from first principles whether (and if so how) we can relate many-worlds theories to empirical data.

I review some interesting and ingenious attempts in this direction by Wallace, Greaves-Myrvold and others, and explain why they don't work.