Symmetries of stationary points of the potential and the framework of the auxiliary group

We classify the constraints on a stationary point of the potential invariant under a finite group into intrinsic and extrinsic based on whether they are independent of the coefficients in the potential or not. We find that the symmetry group of a set of stationary points can be larger than that of the potential and the stabilizer under this group generates intrinsic constraints. By applying these findings in the framework of the auxiliary group, we show that the constraints that can only be obtained extrinsically in an elementary theory can be generated intrinsically in an effective theory. This may be of interest in models where a stationary point of the potential spontaneously breaks discrete symmetries, especially in flavor models of neutrino mixing.