发表机构
School of Physics and Astronomy, Sun Yat-sen University; CSST Science Center for the Guangdong-Hong Kong-Macau Greater Bay Area（中山大学物理与天文学院; 粤港澳大湾区子午线工程科学中心）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
该研究将轴子宇宙与负宇宙学常数结合，应用人择论证，预测特定Ω_m范围概率，解决暗能量问题。排除慢滚和快滚，预测中等滚动力学，给出双参数化。当前数据对ΛCDM和幽灵模型有拒绝倾向，对ALAverse有偏好，未来可进一步检验。
AI 中文摘要
我们将源自弦景观的轴子宇宙与负宇宙学常数Λ相结合，并应用观测时间加权的人择论证。在Λ上采用均匀先验，并采用与约化普朗克尺度相当的典型弦动机轴子衰变常数，该框架预测观测到0.1 <Ω_m <0.9的概率约为40%，从而自然地解决了暗能量长期存在的微调与巧合问题。与许多标量场暗能量模型不同，人择Λ-轴子宇宙（ALAverse）在统计上不支持慢滚动力学，因为慢滚需要对初始场位移进行微调。此外，负宇宙学常数使快滚情景在人择上不利，因为它们通常只产生一个非常短暂的具有正暗能量密度的观测窗口。排除了这两个极端情况后，ALAverse典型地预测了中等滚动力学。我们根据δ_Ω和|ε_s|推导出一个双参数参数化，它涵盖了ALAverse解以及一大类规范场和幽灵场模型。当前观测数据得出δ_Ω = -0.0498±0.0186，对应于对ΛCDM（δ_Ω = 0）和幽灵模型（δ_Ω>0）的2.7σ拒绝。数据还显示对ALAverse比对慢滚 quintessence有轻微偏好，这一趋势可以通过未来对哈勃图的高精度测量进行最终检验。
英文摘要
We combine the axiverse with a negative cosmological constant $Λ$, both originating from the string landscape, and apply an observation-time-weighted anthropic argument. Adopting a uniform prior on $Λ$ and a typical string-motivated axion decay constant comparable to the reduced Planck scale, this framework predicts a $\sim 40\%$ probability of observing $0.1 < Ω_m < 0.9$, thereby naturally resolving the long-standing fine-tuning and coincidence problems of dark energy. Unlike many scalar-field dark energy models, the anthropic Lambda-axion universe (ALAverse) statistically disfavors slow-roll dynamics, as slow-roll requires fine-tuning of the initial field displacement. Moreover, the negative cosmological constant renders fast-roll scenarios anthropically unfavorable, since they typically yield only a very brief observational window with positive dark energy density. Having ruled out both extremes, the ALAverse characteristically predicts a moderate-roll dynamics. We derive a two-parameter parametrization in terms of $δ_Ω$ and $|\varepsilon_s|$ that covers ALAverse solutions as well as a broad class of canonical and phantom field models. Current observational data yield $δ_Ω= -0.0498 \pm 0.0186$, corresponding to a $2.7σ$ rejection of $Λ$CDM ($δ_Ω= 0$) and single-field thawing phantom models ($δ_Ω> 0$). The data also show a mild preference for the ALAverse over slow-roll quintessence, a trend that can be conclusively tested with future high-precision measurements of the Hubble diagram.
Comments3 figures, 1 table; The ALAverse model; PRD accepted version
