Degeneracy of consistency equations in braneworld inflation

In a Randall-Sundrum type II inflationary scenario we compute perturbation amplitudes and spectral indices up to next-to-lowest order in the slow-roll parameters, starting from the well-known lowest-order result for a de Sitter brane. Using two different prescriptions for the tensor amplitude, we show that the braneworld consistency equations are not degenerate with respect to the standard relations and we explore their observational consequences. It is then shown that, while the degeneracy between high- and low-energy regimes can come from suitable values of the cosmological observables, exact functional matching between consistency expressions is plausibly discarded. This result is then extended to the Gauss-Bonnet case.