Constraints on standard model constructions in F-theory

We argue that the following three statements cannot all be true: (i) our vacuum is a type IIB/F-theory vacuum at moderate to large h(1,1); (ii) the alpha' expansion is controlled via the supergravity approximation, a la the Kachru-Kallosh-Linde-Trivedi and Large Volume scenarios; and (iii) there are no additional gauged sectors from 7-branes. Since nearly all known globally consistent F-theory models with the exact chiral spectrum of the Standard Model and gauge coupling unification occur at moderate h(1,1), this finding calls for new moduli stabilization scenarios or/and a rich 7-brane dark sector.