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arXiv · 2308.01012

Testing the $n_s-H_0$ scaling relation with Planck-independent CMB data

Ze-Yu Peng·Yun-Song Piao
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Abstract

In early dark energy (EDE) resolution of Hubble tension, the spectral index $n_s$ of primordial scalar perturbation follows a scaling relation ${\delta n_s}\simeq 0.4\frac{\delta H_0}{H_0}$, where $H_0$ is the Hubble constant. However, this $n_s-H_0$ relation was obtained based on the datasets including Planck cosmic microwave background (CMB) data. In this paper, we investigate this scaling relation with Planck-independent CMB data, i.e. ACT and SPT-3G combined with WMAP(+BAO+Pantheon), respectively. Our results show that the WMAP+SPT-3G dataset also follows this scaling relation, while the WMAP+ACT dataset seems to favor smaller $n_s$, which is related to the fact that the critical redshift $z_c$, at which EDE is excited, favored by the WMAP+ACT dataset is lower and closer to the recombination time.

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Ze-Yu Peng, Yun-Song Piao. 2023-08-02. Testing the $n_s-H_0$ scaling relation with Planck-independent CMB data. https://doi.org/10.1103/physrevd.109.023519

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