论文标题
使用特殊的速度调查来限制结构的生长速度，并具有广角效应
Using peculiar velocity surveys to constrain the growth rate of structure with the wide-angle effect
论文作者
论文摘要
在深色能源的最受欢迎的解释中，有修改的重力理论。星系过度密度和特殊的速度场有助于我们限制结构的生长速率并区分不同的重力模型。我们介绍了一种改进的方法，用于用星系过度密度和特殊的速度场来限制结构的生长速率。该方法通过考虑建模过程中的广角效应和零点校准不确定性来减少建模系统误差。我们还首先在少数基准点计算可能性，然后在MCMC采样期间插值可能性值，从而加快了后采样的速度约30次。我们在模拟上测试了新方法，我们发现它能够恢复基准的结构增长率。我们将新方法应用于SDSS PV目录，该目录是迄今为止最大的单特速度目录。我们对结构增长率的限制为\（fσ_8= 0.405 _ { - 0.071}^{+0.076} \）\）（stat）\（\ pm 0.009 \）（sys）（sys），在0.073的有效红移处。我们的约束与Planck 2018宇宙学模型\（Fσ_8= 0.448 \）一致。我们改进的方法将对未来的数据进行类似的分析，甚至更大的样本量并涵盖了天空上更大的角度区域。
Amongst the most popular explanations for dark energy are modified theories of gravity. The galaxy overdensity and peculiar velocity fields help us to constrain the growth rate of structure and distinguish different models of gravity. We introduce an improved method for constraining the growth rate of structure with the galaxy overdensity and peculiar velocity fields. This method reduces the modelling systematic error by accounting for the wide-angle effect and the zero-point calibration uncertainty during the modelling process. We also speed up the posterior sampling by around 30 times by first calculating the likelihood at a small number of fiducial points and then interpolating the likelihood values during MCMC sampling. We test the new method on mocks and we find it is able to recover the fiducial growth rate of structure. We applied our new method to the SDSS PV catalogue, which is the largest single peculiar velocity catalogue to date. Our constraint on the growth rate of structure is \(fσ_8 = 0.405_{-0.071}^{+0.076}\) (stat) \(\pm 0.009\) (sys) at the effective redshift of 0.073. Our constraint is consistent with a Planck 2018 cosmological model, \(fσ_8 = 0.448\), within one standard deviation. Our improved methodology will enable similar analysis on future data, with even larger sample sizes and covering larger angular areas on the sky.
