论文标题
镜子黑暗扇区解决方案，伴有时间变化的精细结构常数
Mirror Dark Sector Solution of the Hubble Tension with Time-varying Fine-structure Constant
论文作者
论文摘要
我们探索了Cyr-Racine，GE和Knox（ARXIV：2107.13000（2））引入的模型，该模型通过调用``镜像世界''''镜子世界的``镜像世界'''黑暗扇区''''sarte sector'''镜子密度的固定部分来解决哈勃的张力。尽管它将宇宙微波背景和大规模结构观测与哈勃常数的局部测量进行了调解，但该模型需要原始氦质量分数的值，该值与观测值不符，并预测了大爆炸核合成（BBN）的预测。我们考虑了具有标准氦质量分数的模型的变体，但在光子解耦与其现值脱钩过程中，电磁细胞结构常数略有不同。如果该时期的$α$低于其当前值，而$Δα\ simeq -2 \ times 10^{ - 5} $，那么我们可以实现与Cyr-Racine等人相同的哈勃张力分辨率。但是氦气丰富。作为此类时间进化的一个例子，我们考虑了一个超光标度场的玩具模型，质量$ $ m <4 \ times 10^{ - 29} $ eV，与电磁词相结合，在光子解耦合后演变，该模型在光子解耦合后演变，并且似乎与$α$ a $差异的延迟限制是一致的。
We explore a model introduced by Cyr-Racine, Ge, and Knox (arXiv:2107.13000(2)) that resolves the Hubble tension by invoking a ``mirror world" dark sector with energy density a fixed fraction of the ``ordinary" sector of Lambda-CDM. Although it reconciles cosmic microwave background and large-scale structure observations with local measurements of the Hubble constant, the model requires a value of the primordial Helium mass fraction that is discrepant with observations and with the predictions of Big Bang Nucleosynthesis (BBN). We consider a variant of the model with standard Helium mass fraction but with the value of the electromagnetic fine-structure constant slightly different during photon decoupling from its present value. If $α$ at that epoch is lower than its current value by $Δα\simeq -2\times 10^{-5}$, then we can achieve the same Hubble tension resolution as in Cyr-Racine, et al. but with consistent Helium abundance. As an example of such time-evolution, we consider a toy model of an ultra-light scalar field, with mass $m <4\times 10^{-29}$ eV, coupled to electromagnetism, which evolves after photon decoupling and that appears to be consistent with late-time constraints on $α$ variation and the weak equivalence principle.
