The minimal flavour violating axion and its effect on $\Delta N_{eff}$

We study a possible solution to the Strong CP Problem in the Minimal FlavourViolation (MFV) framework. An Abelian factor of the complete flavour symmetry ofthe fermionic kinetic terms is identified as the Peccei-Quinn symmetry intraditional axion models. Its spontaneous breaking generates the MFV axion,which could dynamically make the QCD theta parameter vanish. This model ischaracterized by the way its couplings to fermions are related to the flavourstructure, and describes flavour non-universality effects but not flavourviolation, in contrast to other flavoured axion models like the Axiflavon orFlaxion. We discuss the phenomenology of the MFV axion model taking into accountastrophysical, collider and flavour data, as well as its possible detectionthrough cosmological observables.