### Abstract

Making use of the operator product expansion, we derive a general class of sum rules for the imaginary part of the single-particle self-energy of the unitary Fermi gas. The sum rules are analyzed numerically with the help of the maximum entropy method, which allows us to extract the single-particle spectral density as a function of both energy and momentum. These spectral densities contain basic information on the properties of the unitary Fermi gas, such as the dispersion relation and the superfluid pairing gap, for which we obtain reasonable agreement with the available results based on quantum Monte-Carlo simulations.

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

Pages (from-to) | 467-497 |

Number of pages | 31 |

Journal | Annals of Physics |

Volume | 356 |

DOIs | |

Publication status | Published - 2015 May 1 |

### Fingerprint

### Keywords

- Maximum entropy method
- Operator product expansion
- Sum rules
- Unitary Fermi gas

### ASJC Scopus subject areas

- Physics and Astronomy(all)

### Cite this

*Annals of Physics*,

*356*, 467-497. https://doi.org/10.1016/j.aop.2015.03.007

**Single-particle spectral density of the unitary Fermi gas : Novel approach based on the operator product expansion, sum rules and the maximum entropy method.** / Gubler, Philipp; Yamamoto, Naoki; Hatsuda, Tetsuo; Nishida, Yusuke.

Research output: Contribution to journal › Article

*Annals of Physics*, vol. 356, pp. 467-497. https://doi.org/10.1016/j.aop.2015.03.007

}

TY - JOUR

T1 - Single-particle spectral density of the unitary Fermi gas

T2 - Novel approach based on the operator product expansion, sum rules and the maximum entropy method

AU - Gubler, Philipp

AU - Yamamoto, Naoki

AU - Hatsuda, Tetsuo

AU - Nishida, Yusuke

PY - 2015/5/1

Y1 - 2015/5/1

N2 - Making use of the operator product expansion, we derive a general class of sum rules for the imaginary part of the single-particle self-energy of the unitary Fermi gas. The sum rules are analyzed numerically with the help of the maximum entropy method, which allows us to extract the single-particle spectral density as a function of both energy and momentum. These spectral densities contain basic information on the properties of the unitary Fermi gas, such as the dispersion relation and the superfluid pairing gap, for which we obtain reasonable agreement with the available results based on quantum Monte-Carlo simulations.

AB - Making use of the operator product expansion, we derive a general class of sum rules for the imaginary part of the single-particle self-energy of the unitary Fermi gas. The sum rules are analyzed numerically with the help of the maximum entropy method, which allows us to extract the single-particle spectral density as a function of both energy and momentum. These spectral densities contain basic information on the properties of the unitary Fermi gas, such as the dispersion relation and the superfluid pairing gap, for which we obtain reasonable agreement with the available results based on quantum Monte-Carlo simulations.

KW - Maximum entropy method

KW - Operator product expansion

KW - Sum rules

KW - Unitary Fermi gas

UR - http://www.scopus.com/inward/record.url?scp=84926342647&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=84926342647&partnerID=8YFLogxK

U2 - 10.1016/j.aop.2015.03.007

DO - 10.1016/j.aop.2015.03.007

M3 - Article

AN - SCOPUS:84926342647

VL - 356

SP - 467

EP - 497

JO - Annals of Physics

JF - Annals of Physics

SN - 0003-4916

ER -