Specific-heat amplitude ratio near a Lifshitz point

The specific-heat amplitude ratio $A_{+}{/A}_{-}$ (SHAR) in the neighborhood of an $m$-type Lifshitz point has been calculated in the Gaussian approximation. The crossover behavior of the SHAR between the Lifshitz behavior and the usual isotropic critical behavior is considered. This crossover turns out to depend on the temperature as well as the anisotropy of the dispersion. Renormalization-group calculations in one-loop order of the SHAR generalize the result for the usual isotropic critical point.