Logarithmic Potential Braneworld in Light of the Recent Experiment Observation

Abstract

In the loop inflation standard case, the spectral index n_s depends only on the e-folds number N, and it is larger than the value given by observational measurements, the ratio of tensor to scalar perturbations r is very small so that the gravitational waves are negligible. Therefore, we reconsider this model in the framework of the Randall-Sundrum II braneworld scenario. In this context, we have computed and discussed the perturbation of the scalar curvature and determined the energy scale V₀; and the brane tension value λ. We showed that the various inflationary spectrum perturbation parameters (n_s, r and dn_s/d(ln k) ) depend on N and on the coupling constant α, and we reproduce the central value of the first parameter n_s ∼ 0.96. Also, the ratio r and the running dn_s/d(ln k) are in perfect agreement with the experimental observations (Planck 2015).