Mass spectrum of type IIB flux compactifications -- comments on AdS vacua and conformal dimensions

In this note we study the mass spectrum of type IIB flux compactifications. We first give a general discussion of the mass matrix for F-term vacua in four-dimensional N=1 supergravity theories and then specialize to type IIB Calabi-Yau orientifold compactifications in the presence of geometric and non-geometric fluxes. F-term vacua in this setting are in general AdS${}_4$ vacua for which we compute the conformal dimensions of operators dual to the scalar fields. For the mirror-dual of the DGKT construction we find that one-loop corrections to the complex-structure moduli space lead to real-valued conformal dimensions - only when ignoring these corrections we recover the integer values previously reported in the literature. For an example of a flux configurations more general than the DGKT mirror we also obtain non-integer conformal dimensions. Furthermore, we argue that stabilizing moduli in asymptotic regions of moduli space implies that at least one of the mass eigenvalue diverges.