ADG : Automated generation and evaluation of many-body diagrams II. Particle-number projected Bogoliubov many-body perturbation theory

Autor: Thomas Duguet, P. Arthuis, Alexander Tichai, J. Ripoche
Přispěvatelé: Institut de Recherches sur les lois Fondamentales de l'Univers (IRFU), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Université Paris-Saclay, Direction des Applications Militaires (DAM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)
Jazyk: angličtina
Rok vydání: 2021
Předmět:
Nuclear Theory
[PHYS.NUCL]Physics [physics]/Nuclear Theory [nucl-th]
Computer science
Atomic Physics (physics.atom-ph)
Diagonal
Diagrammatic expansion
General Physics and Astronomy
FOS: Physical sciences
Perturbation theory
01 natural sciences
Physics - Atomic Physics
010305 fluids & plasmas
Nuclear Theory (nucl-th)
Condensed Matter - Strongly Correlated Electrons
symbols.namesake
Physics - Chemical Physics
0103 physical sciences
Feynman diagram
Adjacency matrix
Algebraic expression
010306 general physics
Chemical Physics (physics.chem-ph)
Many-body theory
[PHYS]Physics [physics]
Strongly Correlated Electrons (cond-mat.str-el)
Graph theory
[PHYS.PHYS.PHYS-GEN-PH]Physics [physics]/Physics [physics]/General Physics [physics.gen-ph]
Algebra
Diagrammatic reasoning
Hardware and Architecture
Ab initio
symbols
Perturbation theory (quantum mechanics)
Tuple
Zdroj: Comput.Phys.Commun.
Comput.Phys.Commun., 2021, 261, pp.107677. ⟨10.1016/j.cpc.2020.107677⟩
Popis: We describe the second version (v2.0.0) of the code ADG that automatically (1) generates all valid off-diagonal Bogoliubov many-body perturbation theory diagrams at play in particle-number projected Bogoliubov many-body perturbation theory (PNP-BMBPT) and (2) evaluates their algebraic expression to be implemented for numerical applications. This is achieved at any perturbative order $p$ for a Hamiltonian containing both two-body (four-legs) and three-body (six-legs) interactions (vertices). All valid off-diagonal BMBPT diagrams of order $p$ are systematically generated from the set of diagonal, i.e., unprojected, BMBPT diagrams. The production of the latter were described at length in https://doi.org/10.1016/j.cpc.2018.11.023 dealing with the first version of ADG. The automated evaluation of off-diagonal BMBPT diagrams relies both on the application of algebraic Feynman's rules and on the identification of a powerful diagrammatic rule providing the result of the remaining $p$-tuple time integral. The new diagrammatic rule generalizes the one already identified in https://doi.org/10.1016/j.cpc.2018.11.023 to evaluate diagonal BMBPT diagrams independently of their perturbative order and topology. The code ADG is written in Python3 and uses the graph manipulation package NetworkX. The code is kept flexible enough to be further expanded throughout the years to tackle the diagrammatics at play in various many-body formalisms that already exist or are yet to be formulated.
Comment: 24 pages, 14 figures and one table. Associated code available on https://github.com/adgproject/adg/
Databáze: OpenAIRE