Global approximations to correlation functions of strongly interacting quantum field theories

Fuente: arXiv
Enregistré dans:
Détails bibliographiques
Auteurs principaux: Zhu, Yuanran, Yu, Yang, Kökcü, Efekan, Gull, Emanuel, Yang, Chao
Format: Preprint
Publié: 2025
Sujets:
Accès en ligne:
Tags: Ajouter un tag
Pas de tags, Soyez le premier à ajouter un tag!
_version_ 1866918488554078208
author Zhu, Yuanran
Yu, Yang
Kökcü, Efekan
Gull, Emanuel
Yang, Chao
author_facet Zhu, Yuanran
Yu, Yang
Kökcü, Efekan
Gull, Emanuel
Yang, Chao
contents We introduce a method for constructing global approximations to correlation functions of strongly interacting quantum field theories, starting from perturbative results. The key idea is to employ interpolation method, such as the two-point Padé expansion, to interpolate the weak and strong coupling expansions of correlation function. We benchmark this many-body interpolation approach on two prototypical models: the lattice $ϕ^4$ field theory and the 2D Hubbard model. For the $ϕ^4$ theory, the resulting two point Padé approximants exhibit uniform and global convergence to the exact correlation function. For the Hubbard model, we show that even at second order, the Padé appproximant already provides reasonable characterization of the Matsubara Green's function for a wide range of parameters. Finally, we offer a heuristic explanation for these convergence properties based on analytic function theory.
format Preprint
id arxiv_https___arxiv_org_abs_2512_18532
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Global approximations to correlation functions of strongly interacting quantum field theories
Zhu, Yuanran
Yu, Yang
Kökcü, Efekan
Gull, Emanuel
Yang, Chao
Strongly Correlated Electrons
High Energy Physics - Theory
Quantum Physics
We introduce a method for constructing global approximations to correlation functions of strongly interacting quantum field theories, starting from perturbative results. The key idea is to employ interpolation method, such as the two-point Padé expansion, to interpolate the weak and strong coupling expansions of correlation function. We benchmark this many-body interpolation approach on two prototypical models: the lattice $ϕ^4$ field theory and the 2D Hubbard model. For the $ϕ^4$ theory, the resulting two point Padé approximants exhibit uniform and global convergence to the exact correlation function. For the Hubbard model, we show that even at second order, the Padé appproximant already provides reasonable characterization of the Matsubara Green's function for a wide range of parameters. Finally, we offer a heuristic explanation for these convergence properties based on analytic function theory.
title Global approximations to correlation functions of strongly interacting quantum field theories
topic Strongly Correlated Electrons
High Energy Physics - Theory
Quantum Physics
url https://arxiv.org/abs/2512.18532