Early observations with the James Webb Space Telescope (JWST) have revealed the existence of an unexpectedly large abundance of extremely massive galaxies at redshifts z ≳ 5: these are in tension with the predictions not only of the standard ΛCDM cosmology, but also with those of a wide class of dynamical dark energy (DE) models, and are generally in better agreement with models characterized by a phantom behaviour. Here we consider a model, inspired by string theory and the ubiquity of anti-de Sitter vacua therein, featuring an evolving DE component with positive energy density on top of a negative cosmological constant, argued in an earlier exploratory analysis to potentially be able to explain the JWST observations. We perform a robust comparison of this model against JWST data, considering both photometric observations from the CEERS program, and spectroscopic observations from the FRESCO survey. We show that the model is able to accommodate the JWST observations, with a consistency probability of up to 98%, even in the presence of an evolving component with a quintessence-like behaviour (easier to accommodate theoretically compared to phantom DE), while remaining consistent with standard low-redshift probes. Our results showcase the potential of measurements of high-redshift galaxy abundances in tests of fundamental physics, and their complementarity with standard cosmological probes.

中文翻译：

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暗能量领域的负宇宙学常数：JWST 对高红移星系的光度和光谱观测的测试


詹姆斯·韦伯太空望远镜（JWST）的早期观测揭示了红移时存在数量惊人的极大质量星系z ≳ 5：这些不仅与标准 ΛCDM 宇宙学的预测存在冲突，而且与一大类动态暗能量 (DE) 模型的预测存在冲突，并且通常与以幻影行为为特征的模型更加一致。在这里，我们考虑一个模型，其灵感来自于弦理论和其中无处不在的反德西特真空，其特点是在负宇宙常数之上具有正能量密度的不断演化的 DE 分量，在早期的探索性分析中认为可能能够解释JWST 观测结果。我们将此模型与 JWST 数据进行了稳健的比较，同时考虑了 CEERS 计划的光度观测和 FRESCO 调查的光谱观测。我们表明，该模型能够适应 JWST 观测结果，即使存在具有类似精髓行为的演化组件（理论上比模型 DE 更容易适应），一致性概率高达 98%，同时保持与标准低红移探针一致。我们的结果展示了在基础物理测试中测量高红移星系丰度的潜力，以及它们与标准宇宙学探测器的互补性。