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 .