Scalar fields on pAdS

We obtain a subgroup of the isometry group of $p$AdS (a $p$-adic version of AdS alternative to the Bruhat-Tits tree). We propose a candidate for the scalar bulk action and equation of motion on $p$AdS, and work out analytical expressions of the Green's functions for a particular choice of parameter together with an ansatz for general cases. The limiting behaviors of the Green's function are also studied. With their help, the convergence of small loops (whose radii are smaller than AdS length scale of $p$AdS) is analyzed.