The Extended Einstein–Maxwell-Aether-Axion Theory: Effective Metric as an Instrument of the Aetheric Control over the Axion Dynamics

In the framework of the Einstein–Maxwell-aether-axion theory, we consider a self-consistent model based on the concept of two-level control, which is carried out by the dynamic aether over the behavior of an axionically active electrodynamic system. The Lagrangian of this model contains two guiding functions, which depend on four differential invariants of the aether velocity: the scalar of expansion of the aether flow, the square of the acceleration four-vector, the squares of the shear and vorticity tensors. The guiding function of the first type is an element of the effective aetheric metric; this effective metric is involved in the formulation of kinetic terms for the vector, pseudoscalar and electromagnetic fields and predetermines features of their evolution. The guiding function of the second type is associated with the distribution of axions and describes its vacuum average value; basically, this function appears in the potential of the axion field and predetermines the position and depth of its minima. The self-consistent set of coupled master equations of the model is derived. An example of a static spherically symmetric system is considered as an application.