On inflation potentials in kinetic coupling scenarios

Abstract

In this work, we propose and investigate an inflationary model with a kinetic coupling term [Formula: see text] and a combined scalar potential [Formula: see text]. Exploiting the dynamical system analysis, we identify the stationary points and examine their stability showing certain restrictions on the involved parameters [Formula: see text], [Formula: see text] and [Formula: see text]. Then, we compute and study the relevant observable quantities such as the spectral index [Formula: see text] and the tensor-to-scalar ratio [Formula: see text] from slow-roll approximations. For certain values of the restricted parameters, we find that [Formula: see text] and [Formula: see text] are in a good agreement with the current observation data. To support such findings, we consider the limit corresponding to the vanishing kinetic coupling contribution. We find that this limit provides a boomerang-like geometry intersecting almost all Planck contours associated with the [Formula: see text] curves.