Closed Strings and Moduli in $AdS_3/CFT_2$

Understand

String theory on $AdS_3 \times S^3 \times T^4$ has 20 moduli.

• We investigate how the perturbative closed string spectrum changes as we move around this moduli space in both the RR and NSNS flux backgrounds.
• We find that, at weak string coupling, only four of the moduli affect the energies.
• In the RR background the only effect of these moduli is to change the radius of curvature of the background.