Journal of Physical Studies 7(2), 140–155 (2003)
DOI: https://doi.org/10.30970/jps.07.140 ZETA FUNCTION REGULARIZATION OF INFRARED DIVERGENCES IN BOSE-EINSTEIN CONDENSATIONA. M. J. Schakel
Institut für Theoretische Physik Freie Universität Berlin |
A perturbative calculation of the effect of fluctuations in the \textit{nonzero} frequency modes of a weakly interacting Bose gas on the condensation temperature is reviewed. These dynamic modes, discarded in most of the recent studies, have a temperature-induced energy gap that allows for a perturbative approach. The simple, yet powerful algorithm consists of a high-temperature expansion in conjunction with zeta function regularization of infrared divergences. The algorithm is shown to be reliable by demonstrating that it reproduces known results for a series of examples. With two-loop contributions properly included, the dynamic modes are seen not to lead to a shift in the condensation temperature.
PACS number(s): 03.75.Fi, 11.10.Wx.