Abstract:
Wilson’s renormalization-group approach to the weakly-interacting single-component Bose gas is discussed within the symmetry-broken, condensate phase. Extending upon the work by Bijlsma and Stoof, wave-function renormalization of the temporal derivative contributions to the effective action is included in order to capture sound-like quasiparticle excitations with wave lengths larger than the healing-length scale. By means of a suitable rescaling scheme we achieve convergence of the coupling flows, which serve as a means to determine the condensate depletion in accordance with Bogoliubov theory, as well as the interaction-induced shift of the critical temperature.
N. Rasch, A. N. Mikheev, T. Gasenzer, „Bogoliubov phonons in a Bose-Einstein condensate from
the one-loop perturbative renormalization group“, SciPost Phys. Core 7, 066 (2024).
https://www.scipost.org/SciPostPhysCore.7.3.066
Related to Project A04