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 [Phys. Rev. A 54, 5085 (1996)], 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“, 29. Feb. 2024, arXiv:2402.19239 (2024).


Related to Project A04