9619854 Ashcroft This theoretical grant supports a broad-based research program dealing with various properties of condensed matter systems. There are three specific topics to be studied: dense and metallic hydrogen; general many-body theory; and, density functional theory. Theoretical studies will be done on dense and metallic hydrogen and will include transport properties of dense fluid hydrogen; novel broken symmetry states; pairing of pairs; and, persistence of proton-pairing. Under general many-body theory, topics will include effective electron- electron interactions in reduced dimensions; instabilities in layered systems; two-component quantum systems and generalized scaling; revisiting lithium as a model system for Eliashberg equations of superconductivity; and, helium in a periodic field. Topics in density functional theory will include studies of fullerenes and intercalated fullerenes; the Born-Green equation; the average-ion mixing rule; statistical description of the dynamic crystalline state; and, coarse graining and the inhomogeneous electron gas. %%% This theoretical grant involves research on a wide variety of topics from condensed matter physics - the study of atoms and molecules in condensed states such as liquids and solids. Of particular current interest will be the study of hydrogen, the most abundant element in the universe and usually in a gaseous state, and its properties as it enters a metallic state in which it can conduct electricity. Other topics of study will include superconductivity and the study of fullerenes - a new form of carbon. ***
