Progress of Theoretical Physics Vol. Density Functional Theory through Legendre Transformation Reijiro Fukuda, Takao Kotani, Yoko Suzuki and Satoshi Yokojima pp. 833-862 Theoretical foundation of density functional theory in terms of field theoretical Legendre transformation is presented. The ground state energy is first written as a functional of local probe coupled to the density operator. The density functional is then defined by the functional Legendre transformation, which leads to a systematic formulation of density functional theory.
Excitation spectrum is also determined within the same formalism in a unified way.
The diagrammatic evaluation is most conveniently done by using auxiliary field method. Several generalizations of the formalism and extension to the case other than the density operator are also discussed. The Progress of Theoretical Physics 2000 All rights reserved.