Abstract
We explore the short-time evolution of an SU(N) Fermi-liquid following the quench of a SU(N)-symmetry interaction. The conditions for the existence of a pre-thermalized regime after turning on the interaction strength are analyzed. We find that spin-changing collisions play an important role in suppressing pre-thermalization for spin-polarized initial states. For an unpolarized (i.e. SU$(N)$ symmetric) initial ground state, a pre-thermalized regime is observed, which is robust to presence of (SU$(N)$-symmetric) interactions in the initial state. We also study the short-time dynamics for finite-time ramps of the interaction strength. For long ramp-time, the value of the discontinuity approaches the equilibrium value of the post-quench Hamiltonian.