Off-equilibrium confined dynamics in a glassy system with level-crossing states

We study analytically the dynamics of a generalized p -spin model, starting with a thermalized initial condition. The model presents birth and death of states, hence the dynamics (even starting at equilibrium) may go out of equilibrium when the temperature is varied. We give a full description of this constrained out-of-equilibrium behavior and we clarify the connection to the thermodynamics by computing (subdominant) TAP states, constrained to the starting equilibrium configuration. © 2006 The American Physical Society.