Convergence of the free energy for spherical spin glasses
arXiv:2203.09291 · doi:10.1007/s10955-022-02988-2
Abstract
We prove that the free energy of any spherical mixed -spin model converges as the dimension tends to infinity. While the convergence is a consequence of the Parisi formula, the proof we give is independent of the formula and uses the well-known Guerra-Toninelli interpolation method. The latter was invented for models with Ising spins to prove that the free energy is super-additive and therefore (normalized by ) converges. In the spherical case, however, the configuration space is not a product space and the interpolation cannot be applied directly. We first relate the free energy on the sphere of dimension to a free energy defined on the product of spheres in dimensions and to which we then apply the interpolation method. This yields an approximate super-additivity which is sufficient to prove the convergence.