AdS/CFT correspondence for the $O(N)$ invariant critical φ⁴ model in 3-dimensions by the conformal smearing

We investigate a structure of a 4-dimensional bulk space constructed from the $O(N)$ invariant critical φ⁴ model in 3-dimension using the conformal smearing. We calculate a bulk metric corresponding to the information metric and the bulk-to-boundary propagator for a composite scalar field φ² in the large N expansion. We show that the bulk metric describes an asymptotic AdS space at both UV (near boundary) and IR (deep in the bulk) limits, which correspond to the asymptotic free UV fixed point and the Wilson-Fischer IR fixed point of the 3-dimensional φ⁴ model, respectively. The bulk-to-boundary scalar propagator, on the other hand, encodes Δφ² (the conformal dimension of φ²) into its z (a coordinate in the extra direction of the AdS space) dependence. Namely it correctly reproduces not only Δφ²=1 at UV fixed point but also Δφ²=2 at the IR fixed point for the boundary theory. Moreover, we confirm consistency with the GKP-Witten relation in the interacting theory that the coefficient of the z^Δφ² term in z→ 0 limit agrees exactly with the two-point function of φ² including an effect of the φ⁴ interaction.