Type IIB string theory on AdS5×Tnn′

We study Kaluza-Klein spectrum of type IIB string theory compactified on AdS5×Tnn′ in the context of AdS/CFT correspondence. We examine some of the modes of the complexified 2 form potential as an example and show that for the states at the bottom of the Kaluza-Klein tower the corresponding d=4 boundary field operators have rational conformal dimensions. The masses of some of the fermionic modes in the bottom of each tower as functions of the R charge in the boundary conformal theory are also rational. Furthermore the modes in the bottom of the towers originating from q forms on T11 can be put in correspondence with the BRS cohomology classes of the c=1 non critical string theory with ghost number q.