Approximate reconstruction of inflationary potential with ACT observations

Fuente: arXiv
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Main Authors: Yi, Zhu, Wang, Xingzhi, Gao, Qing, Gong, Yungui
Format: Preprint
Published: 2025
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_version_ 1866918197415903232
author Yi, Zhu
Wang, Xingzhi
Gao, Qing
Gong, Yungui
author_facet Yi, Zhu
Wang, Xingzhi
Gao, Qing
Gong, Yungui
contents The Atacama Cosmology Telescope (ACT) has recently reported updated measurements of the scalar spectral index $n_s$, revealing a tension with the predictions of many conventional inflationary models. In this work, we adopt a parameterization of the spectral index in the form $n_s = 1 - p/(N + α)$ with $1.338<p<1.746$, to reconstruct an inflationary potential consistent with the latest ACT data. The resulting potential is the Kachru-Kallosh-Linde-Trivedi (KKLT) potential $V(ϕ) = V_0/[1 + (M/ϕ)^n]$, where the power index is given by $n = 2(p-1)/(2-p)$. The corresponding tensor-to-scalar ratio is approximately $r \approx 16(p-1)/[C (N+α)^p]$ with $C= 2^{2p-1} \left[\sqrt{p-1}/(2-p)\right]^{2p-2} /M^{2p-2}$. Since the reconstruction under the slow-roll approximation is model-independent, the KKLT model can serve as an effective approximation to a broad class of inflationary scenarios that are consistent with the latest ACT measurements of $n_s$, at least on large scales.
format Preprint
id arxiv_https___arxiv_org_abs_2505_10268
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Approximate reconstruction of inflationary potential with ACT observations
Yi, Zhu
Wang, Xingzhi
Gao, Qing
Gong, Yungui
Cosmology and Nongalactic Astrophysics
General Relativity and Quantum Cosmology
The Atacama Cosmology Telescope (ACT) has recently reported updated measurements of the scalar spectral index $n_s$, revealing a tension with the predictions of many conventional inflationary models. In this work, we adopt a parameterization of the spectral index in the form $n_s = 1 - p/(N + α)$ with $1.338<p<1.746$, to reconstruct an inflationary potential consistent with the latest ACT data. The resulting potential is the Kachru-Kallosh-Linde-Trivedi (KKLT) potential $V(ϕ) = V_0/[1 + (M/ϕ)^n]$, where the power index is given by $n = 2(p-1)/(2-p)$. The corresponding tensor-to-scalar ratio is approximately $r \approx 16(p-1)/[C (N+α)^p]$ with $C= 2^{2p-1} \left[\sqrt{p-1}/(2-p)\right]^{2p-2} /M^{2p-2}$. Since the reconstruction under the slow-roll approximation is model-independent, the KKLT model can serve as an effective approximation to a broad class of inflationary scenarios that are consistent with the latest ACT measurements of $n_s$, at least on large scales.
title Approximate reconstruction of inflationary potential with ACT observations
topic Cosmology and Nongalactic Astrophysics
General Relativity and Quantum Cosmology
url https://arxiv.org/abs/2505.10268