Enhancement of structural rearrangement in glassy systems under shear flow
We extend the analysis of the mean field schematic model recently introduced for the description of glass forming liquids to the case of a supercooled fluid subjected to a shear flow of rate $\gamma$. After quenching the system to a low temperature $T$, a slow glassy regime is observed before stationarity is achieved at the characteristic time $\tau_g$. $\tau_g$ is of the order of the usual equilibration time without shear $\tau_g^o$ for weak shear, $\gamma \tau_g ^o<1$. For larger shear, $\gamma \tau_g ^o>1$, local rearrangement of dense regions is instead enhanced by the flow, and $\tau_g \simeq 1/(T\gamma)$.