Discrete Lehmann representation of three-point functions

D Kiese, HUR Strand, K Chen, N Wentzell, O Parcollet… - Physical Review B, 2025 - APS
We present a generalization of the discrete Lehmann representation (DLR) to three-point
correlation and vertex functions in imaginary time and Matsubara frequency. The …

Feynman diagrammatics based on discrete pole representations: A path to renormalized perturbation theories

D Gazizova, L Zhang, E Gull, JPF LeBlanc - Physical Review B, 2024 - APS
By merging algorithmic Matsubara integration with discrete pole representations we present
a procedure to generate fully analytic closed form results for impurity problems at fixed …

Renormalized perturbation theory for fast evaluation of Feynman diagrams on the real frequency axis

MD Burke, M Grandadam, JPF LeBlanc - Physical Review B, 2023 - APS
We present a method to accelerate the numerical evaluation of spatial integrals of Feynman
diagrams when expressed on the real frequency axis. This can be realized through use of a …

Pairing susceptibility in the weakly interacting multilayer Hubbard model evaluated by direct perturbative expansion

R Farid, JPF LeBlanc - Physical Review B, 2024 - APS
We present a systematic study of the interaction, do**, and layer dependence of the dx 2−
y 2-wave pairing susceptibility of the Hubbard model for a stacked 2D square lattice. We …

Symbolic determinant construction of perturbative expansions

I Assi, JPF LeBlanc - Physical Review B, 2024 - APS
We present a symbolic algorithm for the fully analytic treatment of perturbative expansions of
Hamiltonians with general two-body interactions. The method merges well-known analytics …

Pairing susceptibility of the two-dimensional Hubbard model in the thermodynamic limit

R Farid, M Grandadam, JPF LeBlanc - Physical Review B, 2023 - APS
We compute the diagrammatic expansion of the particle-particle susceptibility via algorithmic
Matsubara integration and compute the correlated pairing susceptibility in the …

TorchAmi: Generalized CPU/GPU implementation of algorithmic matsubara integration

MD Burke, JPF LeBlanc - Computer Physics Communications, 2025 - Elsevier
We present torchami, an advanced implementation of algorithmic Matsubara integration
(AMI) that utilizes pytorch as a backend to provide easy parallelization and GPU support …

Lifshitz transition and triplet -wave pairing from the induced ferromagnetic plaquette via spin differentiated nonlocal interaction

R Farid, D Gazizova, BDE McNiven… - arxiv preprint arxiv …, 2025 - arxiv.org
We study the two-dimensional extended Hubbard model on a square lattice and incorporate
spin-differentiated nearest neighbor (NN) interactions where the equal-spin ($ V_ {uu} $) …

Many-body perturbation theory algorithm for multiband systems, Floquet Moiré materials and beyond

IAT Assi - 2023 - research.library.mun.ca
In the first part of this work we introduce the symbolic determinant method (symDET) for
constructing many-body perturbative expansions which is motivated by the Algorithmic …