论文标题
引力波源聚类在光度距离空间中，存在特殊的速度和镜头误差
Gravitational wave source clustering in the luminosity distance space with the presence of peculiar velocity and lensing errors
论文作者
论文摘要
GW数计数可以用作光度距离空间（LDS）中大型结构（LS）的新型示踪剂，就像红移空间中的星系一样。可以获得具有聚类效果的$ d_l-d_a $双重关系。但是，几个LSS引起的误差将污染GW亮度距离测量值，例如宿主星系的特殊速度分散误差以及前景透镜放大倍率。这些效果引起的距离不确定性将使GW聚类从光谱样数据降低到光度法样数据。在本文中，我们研究了这些LSS诱导的距离误差如何修改从LDS聚类推断的宇宙参数精度。我们考虑下一代GW观测值中的两个，即大爆炸天文台（BBO）和爱因斯坦望远镜（ET）。我们预测角直径距离的参数估计误差$ d_a $，光度距离空间哈勃参数$ h_l $和结构增长率$f_lσ_8$借助Fisher矩阵方法。一般而言，GW源群集数据可用于低于$ d_l <5 $ GPC的宇宙学研究，而高于此规模的镜头误差将大大增加。我们发现，对于BBO，可以以$ 10^{ - 3} $的相对误差为$ 10^{ - 2} $以下$ 10^{ - 3} $限制宇宙学参数。速度分散误差在低光度距离范围内主导，而镜头放大误差是较大的光度距离范围内的瓶颈。为了减少镜头错误，我们假设$ 50 \％$删除效率。即使有了这个最佳假设，在光度距离$ d_l = 25 $ gpc处的分数误差增加到$ o（1）$。 ET的结果与BBO的结果相似。由于ET中的GW源号小于BBO的源号，因此相应的结果也会变得更糟。
GW number count can be used as a novel tracer of the large scale structure (LSS) in the luminosity distance space (LDS), just like galaxies in the redshift space. It is possible to obtain the $D_L-D_A$ duality relation with clustering effect. However, several LSS induced errors will contaminate the GW luminosity distance measurement, such as the peculiar velocity dispersion error of the host galaxy as well as the foreground lensing magnification. The distance uncertainties induced from these effects will degrade the GW clustering from a spectroscopic-like data down to a photometric-like data. In this paper, we investigate how these LSS induced distance errors modify our cosmological parameter precision inferred from the LDS clustering. We consider two of the next generation GW observatories, namely the Big Bang Observatory (BBO) and the Einstein Telescope (ET). We forecast the parameter estimation errors on the angular diameter distance $D_A$, luminosity distance space Hubble parameter $H_L$ and structure growth rate $f_Lσ_8$ with a Fisher matrix method. Generally speaking, the GW source clustering data can be used for cosmological studies below $D_L<5$ Gpc, while above this scale the lensing errors will increase significantly. We find that for BBO, it is possible to constrain the cosmological parameters with a relative error of $10^{-3}$ to $10^{-2}$ below $D_L<5$ Gpc. The velocity dispersion error is dominant in the low luminosity distance range, while the lensing magnification error is the bottleneck in the large luminosity distance range. To reduce the lensing error, we assumed a $50\%$ delensing efficiency. Even with this optimal assumption, the fractional error increased to $O(1)$ at luminosity distance $D_L=25$ Gpc. The results for ET are similar as those from BBO. Due to the GW source number in ET is less than that from BBO, the corresponding results also get a bit worse.
