Saved in:
Bibliographic Details
Main Authors: Erhard, Jannis, Ayers, Paul W.
Format: Preprint
Published: 2026
Subjects:
Online Access:https://arxiv.org/abs/2604.06127
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866915921428217856
author Erhard, Jannis
Ayers, Paul W.
author_facet Erhard, Jannis
Ayers, Paul W.
contents We establish necessary and sufficient conditions for the N-representability of the universal one-electron reduced density matrix functional. Functionals satisfying these conditions are guaranteed to yield variational upper bounds on the true energy in one-electron reduced density matrix functional theory, regardless of the strength of the interparticle repulsion. Conversely, any functional violating these conditions will necessarily underestimate the true energy for certain systems. These exact constraints impose a stringent restriction on density matrix functional approximations, as many existing functionals-including the Hartree-Fock functional-appear to violate them. This mathematical formalism, therefore, can guide the development of new approximate functionals and numerical algorithms.
format Preprint
id arxiv_https___arxiv_org_abs_2604_06127
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Necessary and sufficient conditions for the N-representability of functionals of the one-electron reduced density matrix
Erhard, Jannis
Ayers, Paul W.
Quantum Physics
We establish necessary and sufficient conditions for the N-representability of the universal one-electron reduced density matrix functional. Functionals satisfying these conditions are guaranteed to yield variational upper bounds on the true energy in one-electron reduced density matrix functional theory, regardless of the strength of the interparticle repulsion. Conversely, any functional violating these conditions will necessarily underestimate the true energy for certain systems. These exact constraints impose a stringent restriction on density matrix functional approximations, as many existing functionals-including the Hartree-Fock functional-appear to violate them. This mathematical formalism, therefore, can guide the development of new approximate functionals and numerical algorithms.
title Necessary and sufficient conditions for the N-representability of functionals of the one-electron reduced density matrix
topic Quantum Physics
url https://arxiv.org/abs/2604.06127