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arXiv 2407.03508hep-phastro-ph.CO
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大爆炸核合成期间的早期暗能量

Early Dark Energy During Big Bang Nucleosynthesis

David McKeen, Afif Omar

备注：
13 pages, 8 figures. Updated to match the published version
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AI总结：

研究大爆炸核合成期间早期暗能量对元素丰度和有效相对论自由度的影响，利用CMB观测限制EDE模型参数，并探讨其能否缓解近期原初氦丰度测量的张力。

摘要：

我们研究了在大爆炸核合成（BBN）期间存在的早期暗能量（EDE）组分对氘与氢的元素丰度比D/H、氦丰度$Y_p$以及有效相对论自由度$N_{\rm eff}$的影响。我们考虑了一个简单的EDE模型，该模型在达到临界时间之前保持恒定。在此临界时间之后，EDE转化为以下三种形式之一：与电磁等离子体相互作用的辐射组分、与等离子体解耦的暗辐射组分，或同样解耦的kination。我们利用CMB观测确定的丰度和$N_{\rm eff}$的测量值，为该EDE模型的输入参数设定了限制。此外，我们探讨了这些参数与BBN输入参数之间的关联：重子与光子之比$\eta_b$、中子寿命$\tau_n$以及中微子数量$N_\nu$。最后，我们研究了该设定能否缓解近期原初氦丰度测量所引入的张力。

英文摘要：

We study the impact of an early dark energy component (EDE) present during big bang nucleosynthesis (BBN) on the elemental abundances of deuterium D/H, and helium $Y_p$, as well as the effective relativistic degrees of freedom $N_{\rm eff}$. We consider a simple model of EDE that is constant up to a critical time. After this critical time, the EDE transitions into either a radiation component that interacts with the electromagnetic plasma, a dark radiation component that is uncoupled from the plasma, or kination that is also uncoupled. We use measured values of the abundances and $N_{\rm eff}$ as determined by CMB observations to establish limits on the input parameters of this EDE model. In addition, we explore how those parameters are correlated with BBN inputs; the baryon to photon ratio $η_b$, neutron lifetime $τ_n$, and number of neutrinos $N_ν$. Finally, we study whether this setup can alleviate the tension introduced by recent measurements of the primordial helium abundance.

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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