  B. Amorim et al., (B.Amorim, R.Roldan, E.Cappelluti, A.Fasolino, F.Guinea,
M.I.Katsnelson, Phys. Rev. B, v. 89, 224307 (2014)) reported the theoretical
investigation of quantum crystalline membranes. In this comment we dismiss
validity of their calculations based on a "natural" estimation of the
ultra-violet (UV) divergent contributions into correlation functions. We claim
that such calculations may not be performed correctly within the long-scale
theory.

Statistical Mechanics