论文标题
星系红移空间双光谱：各向异性的重要性
Galaxy redshift-space bispectrum: the Importance of Being Anisotropic
论文作者
论文摘要
我们预测，通过将双向偏置信号添加到标准，两点和三点的聚类统计分析中引起的好处。特别是，我们预测宇宙学参数约束，包括双光谱较高的多尔斯术语，以及星系功率谱（Monopole Plus Quadrupole）和各向同性Bispectrum（Monopole）数据向量。为此，提出了分析协方差矩阵模型。根据一组模拟星系目录估算的数值协方差矩阵的众所周知术语，对此模板进行了仔细的校准。使用功率谱和各向同性双光谱测量的校准测试后，我们将协方差建模扩展到Galaxy Bispectrum较高的多尔斯。使用此协方差矩阵，我们继续使用适当生成的模拟数据向量进行宇宙学参数推断。包括到十六进制的双光谱，在一组参数$ $（B_1，B_2，F，F，σ_8，F_ \ Mathrm {nl}，α_\ perp，α__\ parloot）上平均30 $ \％$ \ con 30 $ \％ $ k_ \ mathrm {max} = 0.09 \，h $/mpc，同时大大降低了后分布中存在的变性。
We forecast the benefits induced by adding the bispectrum anisotropic signal to the standard, two- and three-point, clustering statistics analysis. In particular, we forecast cosmological parameter constraints including the bispectrum higher multipoles terms together with the galaxy power spectrum (monopole plus quadrupole) and isotropic bispectrum (monopole) data vectors. To do so, an analytical covariance matrix model is presented. This template is carefully calibrated on well-known terms of a numerical covariance matrix estimated from a set of simulated galaxy catalogues. After testing the calibration using the power spectrum and isotropic bispectrum measurements from the same set of simulations, we extend the covariance modelling to the galaxy bispectrum higher multipoles. Using this covariance matrix we proceed to perform cosmological parameter inference using a suitably generated mock data vector. Including the bispectrum mutipoles up to the hexadecapole, yields 1-D $68\%$ credible regions for the set of parameters $(b_1,b_2,f,σ_8,f_\mathrm{NL},α_\perp, α_\parallel)$ tighter by a factor of 30$\%$ on average for $k_\mathrm{max}=0.09\,h$/Mpc, significantly reducing at the same time the degeneracies present in the posterior distribution.
