9312606 Kivelson This proposal concerns the low energy implications of strong electronic correlations. The PI proposes to continue studying: 1) The collective properties of the two-dimensional electron gas in a strong magnetic field, especially the nature of the insulating state (which the PI previously identified as a "Hall Insulator"), and the experiments which have sought to measure the charge of the quasi particles in the fractional quantum Hall effect. 2) The implications of frustrated phase separation for the properties of the cuprate superconductors. 3) The effects of intramolecular correlation effects in molecular solids with particular reference to the alkali-doped fullerenes. 4) The properties of very dirty superconductors especially in two dimensions. %%% This proposal involves the theoretical investigation of, and the new physics involved in, condensed matter systems in which the electrons interact with one another in non-standard ways - that is in ways in which the usual averaged-electron methods break down. The PI proposes to examine such systems - so called "strongly correlated systems" - as follows: a) an electron gas in two dimensions in strong magnetic fields, b) the tendency of certain magnetic materials (antiferromagnets) to phase separate c) possible intramolecular mechanisms for superconductivity in the newly-found alkali-metal doped fullerenes and d) the properties of dirty or disordered superconductors. This type of work is at the forefront of issues in contemporary condensed matter theory. ***