Spreading of Damage in the SK Spherical Spin Glass

By considering the Langevin dynamics of the SK spin glass with a spherical constraint we calculate the asymptotic distance between two real replicas that evolve with the same thermal noise from different initial conditions. Despite the simplicity of the model its dynamics is known to be non trivial and presents aging phenomena. We find that the asymptotic distance between two replicas is maximal for a whole family of initial conditions that are arbitrarily close at t=0 . The asymptotic distance presents a dynamical transition at a temperature equal to the static phase transition one.