Constraining Dark Energy with Stacked Concave Lenses
Constraining Dark Energy with Stacked Concave Lenses
复制标题
用堆叠凹透镜限制暗能量
DOI：
10.3847/1538-4357/ab0648
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发表时间：
2019
期刊：
影响因子：
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通讯作者：
Liping Fu
中科院分区：
文献类型：
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作者：
Fuyu Dong;Jun Zhang;Yu Yu;Xiaohu Yang;Hekun Li;Jiaxin Han;Wentao Luo;Jiajun Zhang;Liping Fu
低密度区受非线性结构形成和重子物理的影响较小。它们是探索暗能量本质的理想场所，暗能量是宇宙加速的可能解释。与需要识别单个空洞的空洞透镜不同，我们研究低密度位置(LDP)周围的堆叠透镜信号，低密度位置(LDP)的定义是在投影中没有前景明亮星系的地方。该方法通过绘制有晕的明亮星系之间的对应关系，允许直接与数值结果进行比较。它产生的透镜信号足够重要，足以区分几种暗能量模型。在这项工作中，我们使用CFHTLenS星表来定义LDP，以及测量它们的背景透镜信号。我们考虑了前景明亮星系的几种不同定义(红移范围和星等截断)。对于宇宙学模型，我们进行了六次模拟：第一组模拟具有相同的初始条件，wde=−1，−0.5，−0.8，−1.2；第二组模拟包括略有不同的Λ清洁发展机制模型和赵等人的w(Z)模型。结果表明，WDE=−=0.5、−=0.8的模型不被看好，其他4个模型都与数据取得了比较一致的结果。
Low-density regions are less affected by the nonlinear structure formation and baryonic physics. They are ideal places for probing the nature of dark energy, a possible explanation for the cosmic acceleration. Unlike void lensing, which requires identifications of individual voids, we study the stacked lensing signals around the low-density positions (LDPs), defined as places that are devoid of foreground bright galaxies in projection. The method allows a direct comparison with numerical results by drawing correspondence between the bright galaxies with halos. It leads to lensing signals that are significant enough for differentiating several dark energy models. In this work, we use the CFHTLenS catalog to define LDPs, as well as measuring their background lensing signals. We consider several different definitions of the foreground bright galaxies (redshift range and magnitude cut). Regarding the cosmological model, we run six simulations: the first set of simulations have the same initial conditions, with wde = −1, −0.5, −0.8, −1.2; the second set of simulations include a slightly different ΛCDM model and a w(z) model from Zhao et al. The lensing results indicate that the models with wde = −0.5, −0.8 are not favored, and the other four models all achieve comparable agreement with the data.