Averaging rheological quantities in descriptions of soft glassy materials - art. no. 030502

Many mean-field models have been introduced to describe the mechanical beha vior of glassy materials. They often rely on averages performed over distri butions of elements or states. We here underline that averaging is a more i ntricate procedure in mechanics than in more classical situations such as p hase transitions in magnetic systems. This leads us to modify the predictio ns of the recently proposed soft glassy rheology model for soft glassy mate rials, for which we suggest that the viscosity should diverge at the glass transition temperature T-g with an exponential form eta similar to exp[A/(T -T-g)].