# Density functional theory for strongly interacting electrons

## TL;DR

This paper introduces a new density functional theory approach for strongly interacting electrons, starting from zero kinetic energy and expanding systematically, offering an alternative to Kohn-Sham methods for complex electronic systems.

## Contribution

It proposes a novel framework that begins from the zero kinetic energy limit and develops an expansion for the energy functional, providing a different perspective on strongly correlated electrons.

## Key findings

- Preliminary results for low-density quantum dots show promise.
- The method reduces the energy minimization to a correlated electron problem with an effective potential.
- Several approximation schemes for the energy functional are discussed.

## Abstract

We present an alternative to the Kohn-Sham formulation of density functional theory for the ground-state properties of strongly interacting electronic systems. The idea is to start from the limit of zero kinetic energy and systematically expand the universal energy functional of the density in powers of a "coupling constant" that controls the magnitude of the kinetic energy. The problem of minimizing the energy is reduced to the solution of a strictly correlated electron problem in the presence of an effective potential, which plays in our theory the same role that the Kohn-Sham potential plays in the traditional formulation. We discuss several schemes for approximating the energy functional, and report preliminary results for low-density quantum dots.