### Abstract

Recently, the spectral expansion of finite temperature two-point functions in integrable quantum field theories was constructed using a finite volume regularization technique and the application of multidimensional residues. In the present work, the original calculation is revisited. By clarifying some details in the residue evaluations, we find and correct some inaccuracies of the previous result. The final result for contributions involving no more than two particles in the intermediate states is presented. The result is verified by proving a symmetry property which follows from the general structure of the spectral expansion, and also by numerical comparison to the discrete finite volume spectral sum. A further consistency check is performed by showing that the expansion satisfies the cluster property up to the order of the evaluation.

Original language | English |
---|---|

Article number | P12002 |

Journal | Journal of Statistical Mechanics: Theory and Experiment |

Volume | 2012 |

Issue number | 12 |

DOIs | |

Publication status | Published - Dec 1 2012 |

### Fingerprint

### Keywords

- correlation functions
- form factors
- integrable quantum field theory

### ASJC Scopus subject areas

- Statistical and Nonlinear Physics
- Statistics and Probability
- Statistics, Probability and Uncertainty

### Cite this

*Journal of Statistical Mechanics: Theory and Experiment*,

*2012*(12), [P12002]. https://doi.org/10.1088/1742-5468/2012/12/P12002