Ability of a physically expanding BEC to evade the condensation bound

Determine whether an experimental setup with a physically expanding Bose–Einstein condensate can evade the condensation-density bound that limits the accessible scale-factor range and thereby enable the study of genuinely late-time effects.

Background

The analysis is constrained by the experimentally accessible scale-factor range: increasing the scale factor changes the condensate density, which must remain within a range compatible with condensation. This prevents direct access to the large scale factors needed to observe the predicted late-time growth of correlation functions.

The paper suggests considering a different setup in which the Bose–Einstein condensate itself expands physically. Whether such a setup would overcome the condensation bound is explicitly left unresolved.