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arXiv · 2605.16772

Constraints on non-canonical chaotic inflation from ACT DR6 and BICEP/Keck data

Wei Yang·Chen-Hao Wu·Ya-Peng Hu
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Abstract

In this study, we precisely evaluated the feasibility of the chaotic inflation model within a non-canonical kinetic framework. By applying the slow-roll approximation and imposing constraints on the equilateral non-Gaussianity $f_{\rm NL}^{\rm equil}$, we imposed constraints on the feasible range of the potential index $n$. We established physical bounds for the non-canonical parameter $\alpha$. To obtain precise parameter constraints, we solved the primordial perturbation equations numerically and conducted a rigorous MCMC analysis by using a comprehensive joint P-ACT-LB-BK18 dataset. For these potentials $n=1/3$, $2/3$, and $1$, our results respectively tightly limit $\alpha$ to the levels of $8.8^{+1.6}_{-2.8}$, $11.7^{+1.7}_{-2.6}$, and $16.4^{+3.7}_{-7.0}$, within the corresponding $1\sigma$ confidence intervals. Meanwhile, the required number of $e$-foldings naturally converges to $N \simeq 54$, without the need for fine-tuning. These findings confirm that non-standard mechanisms can resurrect excluded chaotic inflation models within the $1\sigma$ allowed regions of high-precision cosmological data.

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Wei Yang, Chen-Hao Wu, Ya-Peng Hu. 2026-05-16. Constraints on non-canonical chaotic inflation from ACT DR6 and BICEP/Keck data. https://doi.org/10.1016/j.physletb.2026.140532

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