27 according to which a model on AdS$_{5}$ can be viewed as the dual description of a strongly interacting model on four dimensions. In particular, in AdS/CFT fields localized near the IR brane are interpreted as duals to composite states of the strong sector; in this interpretation the Higgs field is no longer a fundamental field, but only an effective low-energy degree of freedom, just like the KK excitations of the gauge fields. With this choice we are in a sense come full circle, since we started my theoretical explo- ration by considering the GD-BESS model, which gives a 4D low-energy effective description of a strongly interacting sector; we generalized that model first to a moose one, then to a 5-dimensional one; finally, thanks to the AdS/CFT correspondence, we can read the gener- alized 5D model again as an effective description of a strongly interacting theory. The choice b ( y ) = e − 2 ky implies (again by eq. (62)) Let’s look at the spectrum again. In this case, the C and S functions (eq. (45)) are given by: where J$_{i}$ and Y$_{i}$ are Bessel function of the first and of the second kind respectively. In this case, not even the condition for the right charged eigenstates can be solved analytically. However, using standard properties of the Bessel functions it is possible to give an estimate for the first eigenvalue, and for the characteristic spacing between two adjacent states, which is approximately con- stant and equal to Δ M = πke − $^{kπR}$. Notice that for kπR >> 1 the scale given by ¯ M is nothing but M$_{1}$ . 1 ¯ M 2 = 1 4 k 2 ( e 2 $^{kπR}$(2 k $^{2}$( πR ) 2 − 2 kπR + 1) − 1 kπR ) ; (93) S ( y, m ) = e ky 2 k π m ( J$_{1}$ ( m k ) Y$_{1}$ ( e $^{ky}$m k ) − J$_{1}$ ( e $^{ky}$m k ) Y$_{1}$ ( m k ) C ( y, m ) = e ky 2 k π m J$_{1}$ e $^{ky}$m k ) Y$_{0}$ ( m k − J$_{0}$ m k ) Y$_{1}$ ( e $^{ky}$m k )) , (94) M$_{1}$ ≃ $_{k e}$− kπR $_{2}$√$_{2}$ √$_{4}$$_{kπR}$ − 3 , (95) the model has now an extra parameter, the curvature k , in addition to the usual πR , ¯ g$_{5}$ , ˜ g , ˜ g ′ , ˜ v and λ . Eqs. (78), (79) and (80) still hold (with the new definition of ¯ M (93)); then, after fixing the standard EW input parameters, we are left with three free quantities, πR and ¯ g$_{5}$ and k . Then, if we want this model to be a potential solution to the hierarchy problem, as the RS1 model [5], we need to fix the curvature parameter k to be around the Planck scale, M$_{P}$ ≃ 10 19 GeV. Then, to have ¯ M around one TeV, we need kπR ≃ 35.