Response of a Fermi gas to time-dependent perturbations: Riemann-Hilbert approach at non-zero temperatures
Abstract
Description
We provide an exact finite temperature extension to the recently developed Riemann-Hilbert approach for the calculation of response functions in nonadiabatically perturbed (multi-channel) Fermi gases. We give a precise definition of the finite temperature Riemann-Hilbert problem and show that it is equivalent to a zero temperature problem. Using this equivalence, we discuss the solution of the nonequilibrium Fermi-edge singularity problem at finite temperatures.
10 pages, 2 figures; 2 appendices added, a few modifications in the text, typos corrected; published in Phys. Rev. B
10 pages, 2 figures; 2 appendices added, a few modifications in the text, typos corrected; published in Phys. Rev. B