Here, a single field inflationary model driven by a mutated hilltop potential, a subclass of the hilltop models of inflation, is investigated. To constrain the parameter space, we employ the latest r−ns constraints from Planck 2018, BICEP/Keck 2018, and the Atacama Cosmology Telescope (ACT) data, alongside reheating parameters Nre, Tre, and ωre, and the model independent bound on the radiation dominated (RD) era Nrd. Furthermore, the relic gravitational wave (GW) spectrum within the sensitivity domains of future GW detectors are analyzed. By combining CMB, reheating, RD era, and GW constraints, we find for the Planck+BK18 data that the inflationary duration is confined to 46≤N≤56 (95\% CL) and 48.1≤N≤56 (68\% CL). Moreover, the model parameter α is confined to 0.161≤α≤0.890 (95\% CL) and 0.217≤α≤0.815 (68\% CL). Inclusion of the ACT data further tighten the constraints to 54≤N≤56 (95\% CL) and 0.29≤α≤0.62 (95\% CL), thereby enhancing the precision and robustness of the model predictions.
@article{arxiv.2412.12203,
title = {Mutated hilltop inflation in light of Planck/ACT observations},
author = {Iraj Safaei and Soma Heydari and Milad Solbi and Kayoomars Karami},
journal= {arXiv preprint arXiv:2412.12203},
year = {2025}
}