Time and temperature-dependent correlation function of an impurity in a one-dimensional Fermi gas as a Fredholm determinant

O. Gamayun ¹ Andrei G. Pronko ² Mikhail B. Zvonarev ^{3, 4}

New Journal of Physics, Institute of Physics: Open Access Journals, 2016, 18, pp.045005

We investigate a free one-dimensional spinless Fermi gas, and the Tonks-Girardeau gas interacting with a single impurity particle of equal mass. We obtain a Fredholm determinant representation for the time-dependent correlation function of the impurity particle. This representation is valid for an arbitrary temperature and an arbitrary repulsive or attractive impurity-gas $\delta$-function interaction potential. It includes, as particular cases, the representations obtained for zero temperature and arbitrary repulsion in [Nucl. Phys. B 892, 83 (2015)], and for arbitrary temperature and infinite repulsion in [Nucl. Phys. B 520, 594 (1998)].

• 1. INSTITUUT LORENTZ – Instituut Lorentz
• 2. Steklov Institute of Mathematics at St. Petersburg
• 3. ITMO – National Research University of Information Technologies, Mechanics and Optics [St. Petersburg]
• 4. LPTMS – Laboratoire de Physique Théorique et Modèles Statistiques