2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/16800We analyse the effect of thermal fluctuations on the elastic constants of the decoupled lamellar phase of tethered, crystalline membranes. Using a momentum-shell renormalization group technique, we show that the smectic-A -like compressional elastic constant, the in-plane Lamé coefficients, and the cross-coupling elastic constant vanish as (\ln q)^{- a} whereas the bend elastic constant diverges as (\ln q)^{b}, with a, b > 0, as the wavenumber q tends to zero. The exponents a and b satisfy the relation a + 3b = 2.3 pages, no figuresSoft Condensed MatterStatistical Mechanicstext