An exact solution of a Landau model of an order-disorder transition with
activated critical dynamics is presented. The model describes a funnel-shaped
topography of the order parameter space in which the number of energy lowering
trajectories rapidly diminishes as the ordered ground-state is approached. This
leads to an asymmetry in the effective transition rates which results in a
non-exponential relaxation of the order-parameter fluctuations and a
Vogel-Fulcher-Tammann divergence of the relaxation times, typical of a glass
transition. We argue that the Landau model provides a general framework for
studying glassy dynamics in a variety of systems.Comment: 4 pages, 2 figure