Fundamentals of Quantum Complex Action Theory
Nagao, Keiichi / Nielsen, Holger Bech
Quantum theory is formulated via the Feynman path integral, where only a past state is given at first. We could consider another formulation, where both past and future states are provided. In addition, an action is usually taken to be real, but there is a possibility that the action is complex at the fundamental level. Thus, quantum theory can be classified into four types, according to whether the future is included or not, and whether the a...