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arXiv 2603.11706astro-ph.CO
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一个统一的标量场对 $H_0$、$S_8$ 和演变暗能量张力的解析

A Unified Scalar-Field Mechanism for the $H_0$, $S_8$ and Evolving Dark-Energy Tensions

National Technical University of Athens(雅典国立技术大学);National Observatory of Athens(雅典国家天文台)

Gerasimos Kouniatalis

AI总结:

本文提出一个统一的标量场模型,通过早期能量注入和晚期 thawing 行为解决 $H_0$、$S_8$ 和演变暗能量的张力问题。

摘要:

我们提出了一种统一的标量场框架,该框架在标准广义相对论内解决三个当前宇宙学异常:$H_0$张力、对减少的晚期时间聚类($S_8$)的轻微偏好,以及近期关于演变暗能量的迹象。该模型包含一个单个的最小耦合规范标量场,其在由局部隆起叠加在指数尾部上的平滑势中演化。隆起产生了一个在最后散射前的短暂能量注入,增加了膨胀率,减少了声学 horizon,并将 CMB 推测的 $H_0$ 值向上推移。在场释放后,其能量密度通过类似 kination 的相迅速红移,确保早期修改不会作为不想要的晚期时间贡献持续存在。在低红移时,指数尾部驱动类似 quintessence 的演化,自然产生 $w_0> -1$ 和 $w_a < 0$,同时抑制线性结构增长并将 $S_8$ 引向观测上偏好的方向。分析明确展示了这种平滑的单场势如何产生所需的早期增强、快速稀释和晚期时间 thawing 行为。

英文摘要:

We propose a unified scalar-field framework that addresses, within standard general relativity, three current cosmological anomalies: the $H_0$ tension, the mild preference for reduced late-time clustering ($S_8$), and recent indications of evolving dark energy. The model contains a single minimally coupled canonical scalar field evolving in a smooth potential composed of a localized bump superimposed on an exponential tail. The bump generates a transient pre-recombination energy injection that increases the expansion rate before last scattering, reduces the sound horizon, and shifts the CMB-inferred value of $H_0$ upward. After the field is released, its energy density rapidly redshifts through a kination-like phase, ensuring that the early modification does not persist as an unwanted late-time contribution. At low redshift, the exponential tail drives quintessence-like evolution, naturally yielding $w_0>-1$ and $w_a<0$ while suppressing linear structure growth and moving $S_8$ in the observationally preferred direction. The analysis shows explicitly how this smooth single-field potential can produce the required sequence of early enhancement, rapid dilution, and late-time thawing behavior.

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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