Braneworld inflation with a complex scalar field from Planck 2015

We study an inflationary model with a single complex scalar field in the framework of braneworld Randall–Sundrum model type 2. From the scalar curvature perturbation constrained by the recent observation values, and for specific choice of parameters, we can reduce the values of the coupling constant to take the natural values, and we found that the phase theta θ of the inflation field can take the narrow interval. We have also derived all known inflationary parameters ( n s , r and d n s d ln ( k ) ) , which are widely consistent with the recent Planck data for a suitable choice of brane tension value λ .