  We employ the effective field theory approach to analyze the characteristics
of Euclidean wormholes within axion theories. Using this approach, we obtain
non-perturbative instantons in various complex scalar models with and without a
non-minimal coupling to gravity, as well as models featuring the $R^2$ term for
a range of coupling values. This yields a series of analytical expressions for
the axion wormhole action, shedding light on the model parameters and field
dependencies of contributions in both the ultraviolet and infrared domains.
Consequently, model-dependent local operators that disrupt axion shift
symmetries are generated at lower energy levels. This, in turn, provides
crucial insights into the gravitational influences on the axion quality
problem.
