论文标题
量化双光谱i的红移空间变形：原始非高斯性
Quantifying the Redshift Space Distortion of the Bispectrum I: Primordial Non-Gaussianity
论文作者
论文摘要
红移空间双光谱的各向异性包含大量宇宙学信息。这种各向异性取决于三个向量的方向$ {\ bf k_1，k_2，k_3} $相对于视线。在这里，我们在球形谐波中分解了红移空间双光谱，该谐波完全量化了这种各向异性。为了说明这一点，我们考虑了由原始非高斯性产生的双光谱的线性红移空间变形。在平面并行近似中，只有前四个甚至$ \ ell $ $多极具有非零值，并且我们为所有非零多极{\ it i.e.}提供明确的分析表达式，最多$ \ ell = 6，m = 4 $。不同的多极矩与真实空间双光谱的比率仅取决于$β_1$线性红移失真参数和三角形的形状。考虑到所有可能形状的三角形，我们研究了该比率如何取决于$β_1= 1 $的三角形的形状。我们还研究了某些极端三角形形状的$β_1$依赖性。如果将来测量，这些多重矩具有约束$β_1$的潜力。如果人们希望使用RedShift Surveys约束$ f _ {\ text {nl}} $，则此处提供的结果也很重要。
The anisotropy of the redshift space bispectrum contains a wealth of cosmological information. This anisotropy depends on the orientation of three vectors ${\bf k_1,k_2,k_3}$ with respect to the line of sight. Here we have decomposed the redshift space bispectrum in spherical harmonics which completely quantify this anisotropy. To illustrate this we consider linear redshift space distortion of the bispectrum arising from primordial non-Gaussianity. In the plane parallel approximation only the first four even $\ell$ multipoles have non-zero values, and we present explicit analytical expressions for all the non-zero multipoles {\it i.e.} upto $\ell=6,m=4$. The ratio of the different multipole moments to the real space bispectrum depends only on $β_1$ the linear redshift distortion parameter and the shape of the triangle. Considering triangles of all possible shapes, we have studied how this ratio depends on the shape of the triangle for $β_1=1$. We have also studied the $β_1$ dependence for some of the extreme triangle shapes. If measured in future, these multipole moments hold the potential of constraining $β_1$. The results presented here are also important if one wishes to constrain $f_{\text{NL}}$ using redshift surveys.
