Non-canonical Conformal Attractors for Single Field Inflation

Abstract

We extend the idea of conformal attractors in inflation to non-canonical sectors by developing a non-canonical conformally invariant theory from two different approaches. In the first approach, namely, ${\cal N}=1$ supergravity, the construction is more or less phenomenological, where the non-canonical kinetic sector is derived from a particular form of the K\"ahler potential respecting shift symmetry. In the second approach i.e., superconformal theory, we derive the form of the Lagrangian from a superconformal action and it turns out to be exactly of the same form as in the first approach. Conformal breaking of these theories results in a new class of non-canonical models which can govern inflation with modulated shape of the T-models. We further employ this framework to explore inflationary phenomenology with a representative example and show how the form of the K\"ahler potential can possibly be constrained in non-canonical models using the latest confidence contour in the $n_s-r$ plane given by recent Planck and BICEP/Keck results.