Testing Variational Perturbation Theory for Effective Actions Using the Gaudin-Yang Model

Fuente: arXiv
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Main Authors: Sharma, Pranav, Furnstahl, R. J.
Format: Preprint
Published: 2025
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author Sharma, Pranav
Furnstahl, R. J.
author_facet Sharma, Pranav
Furnstahl, R. J.
contents The background field formalism based on effective actions is a compelling framework for developing an effective field theory for nuclear density functional theory. Among the challenges in carrying out this development is handling both the particle-hole and pairing channels beyond the mean-field level, which includes how to incorporate collective degrees of freedom. Here we use the exactly solvable one-dimensional Gaudin-Yang model as a theoretical laboratory to explore candidate approaches. We compare Variational Perturbation Theory (VPT) to ordinary many-body perturbation theory and the inversion method, all to second order in their respective expansions, and verify issues with Hubbard-Stratonovich auxiliary fields. VPT outperforms the other approaches at this level over a wide range of densities. The next steps to extend this approach toward nuclei are outlined.
format Preprint
id arxiv_https___arxiv_org_abs_2506_02919
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Testing Variational Perturbation Theory for Effective Actions Using the Gaudin-Yang Model
Sharma, Pranav
Furnstahl, R. J.
Nuclear Theory
Other Condensed Matter
High Energy Physics - Phenomenology
The background field formalism based on effective actions is a compelling framework for developing an effective field theory for nuclear density functional theory. Among the challenges in carrying out this development is handling both the particle-hole and pairing channels beyond the mean-field level, which includes how to incorporate collective degrees of freedom. Here we use the exactly solvable one-dimensional Gaudin-Yang model as a theoretical laboratory to explore candidate approaches. We compare Variational Perturbation Theory (VPT) to ordinary many-body perturbation theory and the inversion method, all to second order in their respective expansions, and verify issues with Hubbard-Stratonovich auxiliary fields. VPT outperforms the other approaches at this level over a wide range of densities. The next steps to extend this approach toward nuclei are outlined.
title Testing Variational Perturbation Theory for Effective Actions Using the Gaudin-Yang Model
topic Nuclear Theory
Other Condensed Matter
High Energy Physics - Phenomenology
url https://arxiv.org/abs/2506.02919