Quasi-distributions for arbitrary non-commuting operators

We present a new approach for obtaining quantum quasi-probability distributions, P(alpha, beta), for two arbitrary operators, alpha and beta, where a and p are the corresponding c-variables. We show that the quantum expectation value of an arbitrary operator can always be expressed as a phase space integral over alpha and beta, where the integrand is a product of two terms: One dependent only on the quantum state, and the other only on the operator. In this formulation, the concepts of quasi-probability and correspondence rule arise naturally in that simultaneously with the derivation of the quasi-distribution, one obtains the generalization of the concept of correspondence rule for arbitrary operators. (C) 2020 Elsevier B.V. All rights reserved.