On the spectrum of the AdS5 x S5 string at large λ

We put forth a program for perturbatively quantizing the bosonic sector of the IIB superstring on AdS(5) x S-5 in the large radius of curvature R (i.e. flat-space) limit, and in light-cone gauge. Using the quantization of the massive particle on AdS(5) x S-5 as a guiding exercise, we read off the correct scaling of the particle coordinates in the large radius limit. In the corresponding large root lambda = R-2/alpha' limit of the string the oscillator modes must be scaled differently from the zero modes. We compute the bosonic string Hamiltonian in this limit which gives the flat-space mass-squared operator at leading order, followed by a harmonic oscillator potential in the zero modes at subleading order. Using these ingredients we calculate the leading and sub-leading terms in the conformal dimension of the length-four Konishi state in the large-lambda limit. Furthermore we work out the relevant terms of the energy expansion to next-to-next-to leading order, which are plagued by severe ordering ambiguities. This prevents us from determining the corrections to the spectrum at order lambda(-1/4).