Exact Correlation Function at the Lifshitz Points of the Spherical Model

The spin-spin correlation function of the spherical model being precisely at an anisotropic Lifshitz point of arbitrary order is calculated exactly. The results are in agreement with scaling. The scaling function is shown to be universal. The direction-dependent long-range correlations may change from ferromagnetic to antiferromagnetic behaviour and back as the dimension is varied. The form of the scaling function is compared to predictions following from local scale invariance for strongly anisotropic critical systems.