Gauss–Bonnet braneworld and WMAP three year results

Abstract

We compare predictions for the spectral index and tensor-scalar ratio in models of patch inflation with the WMAP three year data. There are three cases of these models of inflation, which arise in the Gauss-Bonnet braneworld scenario: Gauss-Bonnet (GB), Randall-Sundrum (RS), and 4D general relativity (GR). We consider the large-field potential $V \propto \phi^p$ in both commutative and noncommutative spacetimes, and find that in the cases of the GB and GR patch cosmologies, the quadratic potential is observationally favored, while the quartic potential is ruled out in most patches. Strong noncommutative inflation is excluded in all cases because it leads to a blue-tilted scalar spectral index.