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arXiv · 2511.16606

Dark energy after pre-recombination early dark energy in light of DESI DR2 and the latest ACT and SPT data

Hao Wang·Yun-Song Piao
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Abstract

It has been noted that with the pre-recombination early dark energy (EDE) resolution of Hubble tension, the preference of recent datasets for the evolving dark energy (DE) can be suppressed significantly. In this work, we clarify and reconfirm this result with DESI DR2 and the latest ACT DR6 and SPT-3G D1, the tightest small-scale CMB constraints up to date. In the $w_0w_a$CDM model with EDE, a quintessence-like component ($w_0+w_a\geq-1$) can be 1$\sigma$ consistent with Planck+ACT+SPT+DESI+Pantheon+SH0ES datasets, and $\Delta\chi^2\lesssim -14$ compared with $w_0w_a$CDM model without EDE. This reveals the possibility that when the potential resolutions of Hubble tension are considered, current accelerated expansion can attribute to a canonical evolving scalar field or cosmological constant, and again highlights the importance of re-examining the nature of DE within the broader context of cosmological tensions.

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Hao Wang, Yun-Song Piao. 2025-11-20. Dark energy after pre-recombination early dark energy in light of DESI DR2 and the latest ACT and SPT data. https://arxiv.org/abs/2511.16606

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