Fixed-Point String Theory Prediction of Quark--Gluon Plasma Viscosity

This work takes as input a stabilized Kähler modulus with a fixed numerical value of 220, derived independently from vacuum energy suppression in Type IIB string theory. This fixed point uniquely determines the compactification volume, the string scale, and the warp-factor hierarchy in a flux compactification that contains a warped anti–de Sitter throat. Using the resulting flux data to fix the effective ’t Hooft coupling of the dual gauge theory, the shear viscosity to entropy density ratio of the quark–gluon plasma is computed via the anti–de Sitter/conformal field theory (AdS/CFT) correspondence, including the leading string-theoretic correction. The final prediction for the viscosity ratio is 0.0797, obtained without parameter fitting and consistent with values inferred from relativistic heavy-ion collision data.