“…Even in finite volume, the ultraviolet (short-distance) stability of both models is delicate when β 4π (for β < 4π the situation is simpler). For example, various constructions of the sine-Gordon model exist under different assumptions (see in particular [3,6,9,16,17,20,26,36,38,43]), but none of these covers all β ∈ (0, 8π) and all z ∈ R, even for interactions in a fixed finite volume. The analysis of the infinite volume limit is a different problem.…”