Loops in AdS

We study loop amplitudes in AdS in the spectral representation and in position space. We derive identities which enable to compute certain families of loop amplitudes in terms of tree level amplitudes. We study vector models on AdS (The O(N) model and the Gross-Neveu model). We show how the spectral representation enables to derive the 4-point correlator of these models at large N. We derive expressions for 4-point ladder diagrams in AdS.