Speaker
Description
Understanding whether string theory admits AdS vacua with scale separation, i.e. a large hierarchy between the cosmological constant and the Kaluza–Klein scale, remains a central challenge and source of debate in the field. In this context, holography could provide a powerful lens for assessing the consistency of such solutions. Yet, holographic duals to scale-separated vacua remain elusive. Motivated by the expectation that any putative dual must satisfy certain basic properties, recent work has proposed that scale-separated solutions whose mass spectra yield integer conformal dimensions must obey a non-trivial constraint on the cubic couplings of the theory. This criterion has been verified for the so-called DGKT solutions. In this talk, I will test this holographic constraint for a family of AdS$_3$ solutions that exhibit scale separation with an integral spectrum. These solutions arise from compactifications of type II string theory on $\mathbb{Z}_2^3$ orbifolds of twisted tori with $G_2$-structure. I will show that the holographic constraint is not satisfied in these cases, but that it is restored when considering non-abelian orbifolds containing a $\mathbb{Z}_2^3$-subgroup. I will also comment on the analogous situation for AdS$_4$ compactifications on $\mathbb{Z}_2^2$ orbifolds.
