Single-field inflation \`a la generalized Chaplygin gas

Abstract

In the simplest scenario for inflation, i. e. in the single-field inflation, it is presented an inflaton field with properties equivalent to a generalized Chaplygin gas. Their study is performed using the Hamilton-Jacobi approach to cosmology. The main results are contrasted with the measurements recently released by the Planck data, combined with the WMAP large-angle polarization. If the measurements released by Planck for the scalar spectral index together with its running are taken into account it is found a value for the $\alpha$-parameter associated to the generalized Chaplygin gas given by $\alpha = 0.2578 \pm 0.0009$.