论文标题
带浓缩咖啡的基本物理学,限制了不同$α$的简单参数化
Fundamental Physics with ESPRESSO, Constraining a simple parametrisation for varying $α$
论文作者
论文摘要
光谱仪板浓缩咖啡馆最近通过沿着明亮的类星体的视线尺寸,精度为$ 1.36 $ ppm $1σ$级别,对精细结构常数$α$的变化限制了限制。这对宇宙学模型施加了新的限制,其$α$。我们假设电磁扇形与负责宇宙当前加速度的标量磁场暗能量耦合的模型。我们用两个额外的参数来参数$α$的变化,一个定义Quintessence成分的宇宙学演化,另一个定义了与电磁场耦合的固定。这项工作的目的是通过天体物理和局部探针来限制这些参数。我们还对每个数据探针如何限制我们的参数化进行了比较分析。我们通过将模型的预测与观测值进行比较,进行了贝叶斯分析。天体物理数据集由类星体光谱测量值组成,包括最新的意式浓缩咖啡数据点以及宇宙微波背景的普朗克观察结果。我们将它们与原子钟和显微镜实验的局部结果相结合。放置在典型参数上的约束与该场的无效变化一致,因此与$λ$ CDM宇宙学兼容。与电磁扇区耦合的约束由Eötvös参数局部结合主导。浓缩咖啡的更精确的测量对于研究$α$的宇宙学演变非常重要,因为它探测了其他类型的观测值无法访问红移的间隔。但是,对于此特定模型,当前可用的数据有利于$α$的无效变化,这主要是由强显微镜极限产生的。
The spectrograph ESPRESSO recently obtained a limit on the variation of the fine-structure constant, $α$, through measurements along the line of sight of a bright quasar with a precision of $1.36$ ppm at $1σ$ level. This imposes new constraints on cosmological models with a varying $α$. We assume such a model where the electromagnetic sector is coupled to a scalar field dark energy responsible for the current acceleration of the Universe. We parametrise the variation of $α$ with two extra parameters, one defining the cosmological evolution of the quintessence component and the other fixing the coupling with the electromagnetic field. The objective of this work is to constrain these parameters with both astrophysical and local probes. We also carried out a comparative analysis of how each data probe may constrain our parametrisation. We performed a Bayesian analysis by comparing the predictions of the model with observations. The astrophysical datasets are composed of quasar spectra measurements, including the latest ESPRESSO data point, as well as Planck observations of the cosmic microwave background. We combined these with local results from atomic clocks and the MICROSCOPE experiment. The constraints placed on the quintessence parameter are consistent with a null variation of the field, and are therefore compatible with a $Λ$CDM cosmology. The constraints on the coupling to the electromagnetic sector are dominated by the Eötvös parameter local bound. More precise measurements with ESPRESSO will be extremely important to study the cosmological evolution of $α$ as it probes an interval of redshift not accessible to other types of observations. However, for this particular model, current available data favour a null variation of $α$ resulting mostly from the strong MICROSCOPE limits.