From the density functional to the single-particle Green function

TL;DR

This paper demonstrates that the ground state properties of inhomogeneous interacting electron systems in static external fields can only be accurately described using Green function theory derived from quantum field theory methods, emphasizing the importance of the single-particle Green function.

Contribution

It establishes that the Green function approach is essential for consistent description of the ground state energy and density in inhomogeneous electron systems.

Findings

Ground state energy depends on the single-particle Green function.

Inhomogeneous electron density can be obtained from Green function calculations.

Quantum field theory methods are necessary for accurate ground state descriptions.

Abstract

An analysis shows that the ground state of the inhomogeneous system of interacting electrons in the static external field, which satisfies the thermodynamic limit, can be consistently described only using the Green function theory based on the quantum field theory methods (perturbation theory diagram technique). In this case, the ground state energy and inhomogeneous electron density in such a system can be determined only after calculating the single-particle Green function.