Dyson Orbitals, Quasi-Particle effects and Compton scattering

TL;DR

This paper explores how Dyson orbitals can improve the understanding of quasi-particle effects and Compton scattering beyond traditional models, providing a simplified local form of exchange-correlation energy with practical examples.

Contribution

It introduces a new approach to incorporate quasi-particle effects via Dyson orbitals and derives a simple local exchange-correlation energy functional.

Findings

Demonstrates corrections to Kohn-Sham energies using Dyson orbitals

Provides a simplified local form of exchange-correlation energy

Includes illustrative examples showing scheme's usefulness

Abstract

Dyson orbitals play an important role in understanding quasi-particle effects in the correlated ground state of a many-particle system and are relevant for describing the Compton scattering cross section beyond the frameworks of the impulse approximation (IA) and the independent particle model (IPM). Here we discuss corrections to the Kohn-Sham energies due to quasi-particle effects in terms of Dyson orbitals and obtain a relatively simple local form of the exchange-correlation energy. Illustrative examples are presented to show the usefulness of our scheme.