TY  - JOUR
PB  - SciPost Foundation
DO  - 10.21468/SciPostPhys.15.5.183
TI  - Spectral representation of Matsubara n-point functions: Exact kernel functions and applications
PY  - 2023/11/01
UR  - https://scipost.org/SciPostPhys.15.5.183
JF  - SciPost Physics
JA  - SciPost Phys.
VL  - 15
IS  - 5
SP  - 183
A1  - Halbinger, Johannes
AU  - Schneider, Benedikt
AU  - Sbierski, Björn
AB  - In the field of quantum many-body physics, the spectral (or Lehmann) representation simplifies the calculation of Matsubara $n$-point correlation functions if the eigensystem of a Hamiltonian is known. It is expressed via a universal kernel function and a system- and correlator-specific product of matrix elements. Here we provide the kernel functions in full generality, for arbitrary $n$, arbitrary combinations of bosonic or fermionic operators and an arbitrary number of anomalous terms. As an application, we consider bosonic 3- and 4-point correlation functions for the fermionic Hubbard atom and a free spin of length $S$, respectively.
ER  -

@Article{10.21468/SciPostPhys.15.5.183,
	title={{Spectral representation of Matsubara n-point functions: Exact kernel functions and applications}},
	author={Johannes Halbinger and Benedikt Schneider and Björn Sbierski},
	journal={SciPost Phys.},
	volume={15},
	pages={183},
	year={2023},
	publisher={SciPost},
	doi={10.21468/SciPostPhys.15.5.183},
	url={https://scipost.org/10.21468/SciPostPhys.15.5.183},
}