  Rheological properties, especially 'shear-thinning', of dense colloidal
dispersions are discussed on three different levels. A generalized
phenomonological Maxwell model gives a broad framework connecting glassy
dynamics to the linear and non-linear rheology of dense amorphous particle
solutions. First principles mode coupling theory calculations for the time or
frequency dependent shear modulus give quantitative results for dispersions of
hard colloidal spheres in the linear regime. Schematic models extending mode
coupling theory to the non-linear regime recover the phenomenology of the
generalized Maxwell model, and predict universal features of flow curves,
stress versus shear-rate.
