Moduli stabilisation on the worldsheet

Abstract

We consider compactifications of type II string theory using exact internal CFT's with central charge c = 9 + ∈, |∈| < 1, leading to an effective potential for the dilaton. For ∈ > 0 the potential is positive and the dilaton is ultimately driven to weak coupling. For ∈ < 0 the dilaton is driven to strong coupling, but we can stabilise the background by including D-branes. The resulting minimum admits an AdS4 solution where the cosmological constant is of the order ∈3 and the string coupling constant is of order ∈. Furthermore these CFT's typically do not possess any massless or tachyonic modes. Thus these vacua provide exact CFT descriptions of moduli stabilisation in weakly coupled string theory. © SISSA 2011.