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arXiv 1010.3722astro-ph.CO
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一种广义局域自洽及其对Halo偏差的影响

A generalized local ansatz and its effect on halo bias

Sarah Shandera, Neal Dalal, Dragan Huterer

摘要:

受早期宇宙场景产生观测大的局部非高斯性的性质的启发,我们从广义的局部anomaly进行N体模拟与非高斯初始条件。双谱是局部形状的示意图,但具有尺度依赖的幅度。我们发现,在这种情况下,大小的非高斯校正的大小的偏差的小质量和大质量的物体取决于振幅的非高斯大致上的对象的规模。此外,某些形式的广义双谱通过k的分数幂来改变偏置中非高斯项的尺度依赖性。这些特征可以允许对任何观测到的局部非高斯性的粒子物理起源的显著观测约束,区分单个场或多个场对曲率波动有贡献的场景。虽然非高斯偏置的分析预测同意定性与模拟,我们发现数值比预期更强的观测信号。这表明需要对晕的形成有更精确的理解,才能充分解释原始非高斯性的后果

英文摘要:

Motivated by the properties of early universe scenarios that produce observationally large local non-Gaussianity, we perform N-body simulations with non-Gaussian initial conditions from a generalized local ansatz. The bispectra are schematically of the local shape, but with scale-dependent amplitude. We find that in such cases the size of the non-Gaussian correction to the bias of small and large mass objects depends on the amplitude of non-Gaussianity roughly on the scale of the object. In addition, some forms of the generalized bispectrum alter the scale dependence of the non-Gaussian term in the bias by a fractional power of k. These features may allow significant observational constraints on the particle physics origin of any observed local non-Gaussianity, distinguishing between scenarios where a single field or multiple fields contribute to the curvature fluctuations. While analytic predictions for the non-Gaussian bias agree qualitatively with the simulations, we find numerically a stronger observational signal than expected. This suggests that a more precise understanding of halo formation is needed to fully explain the consequences of primordial non-Gaussianity

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