Evolution of the system density with time after two successive temperature jumps: first, at time t = 0, T is decreased from 0.6 to 0.45. Second, at t = 6000, the temperature is increased to T = 0.5 (blue), 0.55 (green), 0.6 (black), or 0.7 (red).
(a) Evolution of the effective relaxation time after the temperature jumps described in Fig. 1 . (b) Close-up of the region where the temperature is increased, and error bars are shown on the low temperature data where our statistical uncertainties are the largest.
(a) Evolution of the average string length after the temperature jumps described in Figs. 1 and 2 . (b) Close-up view of the region where the temperature is increased, and the horizontal lines indicate the equilibrium value of L S at the new set point temperature.
Evolution of the system density (a) and potential energy (b) after T jumps from above and below to a common intermediate temperature, T = 0.5. The black, red, green, and blue curves each represent temperature jumps of Δ = 0.05, 0.025, −0.025, and −0.05, respectively.
(a) Effective relaxation times and (b) average string length after the symmetric temperature jumps described in Fig. 4 . As with the density in Fig. 4(a) , after a temperature decrease, the curves representing the properties quickly merge and drift to the equilibrium value together, while after a temperature increase the curves approach equilibrium at different rates.
(a) Structural relaxation normalized by T g , with the inset representing the average string length; (b) test of the Adam-Gibbs relationship for this model polymer glass at equilibrium. The relaxation times τα and average string length L S are calculated as a function of temperature for systems at equilibrium in the supercooled regime (0.825 > T > 0.45); the line is merely a guide to the eye. τα is calculated at equilibrium as the time for F s (q, t) to decay to 0.2.
Test of the connection between τ eff and the ratio L S /T for systems out of equilibrium. The dashed black line represents the equilibrium results in the supercooled regime, and the various sets of points are from the non-equilibrium, symmetric temperature jump simulations described in Figures 4 and 5 above. Each data set represents a distinct temperature jump, and the arrows indicate the time evolution of the relaxation time and string length.
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