I worked with Adrian Kent on the consistent histories approach to quantum mechanics. This is an objective approach to quantum mechanics which seeks to describe quantum mechanics without subjective ideas such as observers, measurements or classical domains. My earliest work was on different criteria for approximate and exact consistency, and I discovered a surprising connection with the generalized kissing problem. Read the paper.
This work was motivated by investigating set selection algorithms in the consistent histories approach. A general discussion of this approach (written with Dr. A Kent) is here. In another paper a simple quantum system consisting of interacting spin half particle is described and a subset of the exactly consistent sets is classified. This model is used to illustrate the difficulties a set selection algorithm must overcome, but is also used to show that an algorithm based on a maximum information criterion selects physically reasonable sets.