In this report we address the question whether aging in the non equilibrium
glassy state is controlled by the equilibrium alpha-relaxation process which
occur at temperatures above Tg. Recently Lunkenheimer et. al. [Phys. Rev. Lett.
95, 055702 (2005)] proposed a model for the glassy aging data of dielectric
relaxation using a modified Kohlrausch-Williams-Watts (KWW) form. The aging
time dependence of the relaxation time is defined by these authors through a
functional relation involving the corresponding frequency but the stretching
exponent is same as the alpha-relaxation stretching exponent. We present here
an alternative functional form directly involving the relaxation time itself.
The proposed model fits the data of Lunkenheimer et. al. perfectly with a
stretching exponent different from the alpha-relaxation stretching exponent.Comment: 1 TeX file, 10 eps figure
