Abstract

We study a braneworld Randall-Sundrum type II (RSII) model using the Hamilton-Jacobi formalism. We extend the standard inflationary parameters and the flow equations for this braneworld scenario. We investigate the conditions that reduce the infinite number of flow equations into a finite number and confirm that by considering one of the inflationary parameters that vanishes, the Hubble expansion rate gets a polynomial form in both General Relativity (GR) and in the high-energy regime of RSII. We also show that if one sets this inflationary parameter to a constant value, the model features a nonpolynomial form of the Hubble expansion rate. The form of the Hubble parameter in this case is different in GR and RSII. Next, we consider a single-scalar field model with a Hubble expansion rate behaving as H proportional to phi(n) and show that compared to GR, the RSII model has a smaller tensor-to-scalar ratio and larger spectral index for n > 1. Therefore, RSII model leads to better predictions than GR.