Short-Time Dynamics in Phase-Ordering Kinetics

Short-time dynamics in the 2D Blume-Capel model, with a non-conserved order-parameter and short-ranged interactions, is analysed. For non-equilibrium dynamics, both at a critical point in the 2D Ising universality class and at the tricritical point, we reproduce the values Θ=0.190(5) and Θ=-0.542(5), respectively, of the critical initial slip exponent. These agree with more early estimates and with the Janssen-Schaub-Schmittmann scaling relation. In phase-ordering kinetics, after a quench into the ordered phase, we establish the validity of short-time dynamics. In the 2D Ising universality class, we find Θ=0.39(1) in agreement with the scaling relation λ=d-2Θ.