ACT-Inspired Kaehler-Based Inflationary Attractors

TL;DR

This paper introduces a new class of inflationary models inspired by ACT results, utilizing fractional Kaehler potentials within supergravity to achieve subplanckian inflation and high tensor-to-scalar ratios.

Contribution

It develops novel Kaehler-based inflationary attractors compatible with recent data, featuring shift symmetry and supergravity realization, with inflationary predictions largely independent of certain parameters.

Findings

Models produce inflationary observables consistent with current data.

Achieves inflation with subplanckian inflaton values.

Predicts large tensor-to-scalar ratios increasing with N.

Abstract

We develop a new class of cosmological attractors which are compatible with the recent ACT results. They are based on two types of fractional Kaehler potentials, K, for a gauge-singlet inflaton phi which reduce, along the inflationary path, to the form N/(1-phi^qM)^p with qM=1, 2 and 0.1< p<10. The combination of these K's with the chaotic potentials phi^n (where n=2, 4) within a non-linear sigma model leads to inflationary observables which are consistent with the current data and largely independent from qM and n. Endowing these K's with a shift symmetry we also offer a supergravity realization of our models introducing two chiral superfields and a monomial superpotential, linear with respect to the inflaton-accompanying field. The attainment of inflation with subplanckian inflaton values and the large values for the tensor-to-scalar ratio, which increases with N, are two additional attractive features of our proposal.