Simple brane-world inflationary models: an update

Understand

In the light of the Planck 2015 results, we update simple inflationary models based on the quadratic, quartic, Higgs and Coleman-Weinberg potentials in the context of the Randall-Sundrum brane-world cosmology.

• Brane-world cosmological effect alters the inflationary predictions of the spectral index ($n_s$) and the tensor-to-scalar ratio ($r$) from those obtained in the standard cosmology.
• In particular, the tensor-to-scalar ratio is enhanced in the presence of the 5th dimension.
• In order to maintain the consistency with the Planck 2015 results for the inflationary predictions in the standard cosmology, we find a lower bound on the five-dimensional Planck mass ($M_5$).