$\alpha$-Attractor and Reheating in a Model with Non-Canonical Scalar Fields

TL;DR

This paper explores inflationary models with non-canonical scalar fields, specifically tachyon and DBI types, analyzing their predictions for the spectral index and reheating constraints, and comparing results with observational data.

Contribution

It introduces and analyzes $eta$-attractor inflation models with tachyon and DBI fields, extending the understanding of non-canonical inflationary scenarios.

Findings

Spectral index in small alpha limit depends on e-folds, similar to canonical models.

DBI model shows a slightly different spectral index compared to tachyon and canonical cases.

Reheating constraints further restrict model parameters.

Abstract

We consider two non-canonical scalar fields (tachyon and DBI) with E-model type of the potential. We study cosmological inflation in these models to find possible $\alpha$-attractors. We show that similar to the canonical scalar field case, in both tachyon and DBI models there is a value of the scalar spectral index in small $\alpha$ limit which is just a function of the e-folds number. However, the value of $n_{s}$ in DBI model is somewhat different from the other ones. We also compare the results with Planck2015 TT, TE, EE+lowP data. The reheating phase after inflation is studied in these models which gives some more constraints on the model's parameters.