Field theory for the Almeida-Thouless transition

This work contains a review of the theoretical understanding for the Almeida-Thouless transition. The effective field theoretic model for this transition to the replica symmetry broken phase is extended to low temperatures, making it possible to compute perturbative corrections to the mean field phase boundary even close to zero temperature. Nonperturbative behavior emerges both around the zero-external-field transition and at low temperature. Renormalization group results are also discussed.