We discuss the strategy of determining properties of many-body systems by applying successively more stringent limitations on the domain on which solutions can lie, i.e., sharpening the degree of resolution of the results obtained. A rough division is made into universal, or system-independent inequalities and systemdependent ones, which are joined by equalities or sum rules. General examples include Fermion ground states and classical fluids in thermal equilibrium, and for the latter, the effect of estimation by saturating inequalities.
- Density functional
- Reduced density matrix
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics
- Condensed Matter Physics
- Physical and Theoretical Chemistry