Foundations of quantum probability

This paper presents an overview of the foundations of quantum probability. The main concepts in this theory are measurements and generalized actions. These concepts correspond to the usual quantum observables and states. Probabilities are computed by means of a universal influence function. We first derive the form of the universal influence function and then construct the amplitude and probability of a measurement with respect to a given generalized action. It is shown that traditional quantum mechanics can be derived as a special case of this theory and moreover the theory gives a complete realistic interpretation of quantum mechanics. It is demonstrated that spins of any order can be described within this framework and a realistic solution to the EPR problem can be achieved.