Beyond the standard IAU framework

Abstract

We discuss three conceivable scenarios of extension and/or modification of the IAU relativistic resolutions on time scales and spatial coordinates beyond the Standard IAU Framework. These scenarios include: (1) the formalism of the monopole and dipole moment transformations of the metric tensor replacing the scale transformations of time and space coordinates; (2) implementing the parameterized post-Newtonian formalism with two PPN parameters - β and γ; (3) embedding the post-Newtonian barycentric reference system to the Friedman-Robertson-Walker cosmological model.