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arXiv 2211.04087astro-ph.COhep-ph
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基于EMPRESS Y_p结果与H_0张力的宇宙大爆炸核合成与早期暗能量研究

Big bang nucleosynthesis and early dark energy in light of the EMPRESS $Y_p$ results and the $H_0$ tension

Tomo Takahashi, Sora Yamashita

AI总结:

本文结合EMPRESS的Y_p测量与H_0张力,提出扩展标准宇宙学模型,并证明引入早期暗能量可缓解相关矛盾。

摘要:

EMPRESS最近对原初氦-4丰度Y_p的测量表明,存在一种宇宙学情景:有效中微子物种数偏离标准值,且轻子不对称性非零。我们认为,当考虑哈勃张力时,对标准宇宙学模型的扩展将更为必要,因为在此情形下推导出的重子密度可能略高于标准ΛCDM框架所给出的值。我们还通过假设早期暗能量来讨论该问题,早期暗能量的能量密度在宇宙大爆炸核合成时期可能占据相当比例。我们证明,早期暗能量的存在可以缓解EMPRESS Y_p结果所暗示的部分张力。

英文摘要:

Recent measurement of the primordial $^4$He abundance $Y_p$ from EMPRESS suggests a cosmological scenario with the effective number of neutrino species deviated from the standard value and non-zero lepton asymmetry. We argue that the extension of the standard cosmological model would be more demanded when the Hubble tension is taken into account, in which derived baryon density could be somewhat higher than the standard $Λ$CDM framework. We also discuss the issue by assuming early dark energy whose energy density can have a sizable fraction at the epoch of big bang nucleosynthesis. We show that the existence of early dark energy can reduce some tension implied by the EMPRESS $Y_p$ results.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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