论文标题
通过CMB透镜互相关测量的对原始非高斯的限制
Constraints on primordial non-Gaussianity from halo bias measured through CMB lensing cross-correlations
论文作者
论文摘要
在宇宙的初始条件下，局部非高斯，由$ f _ {\ rm nl} $参数化，诱导后期宇宙中光晕的大规模偏置的规模依赖性。这种效果是约束多场通货膨胀理论的有希望的途径，该理论预测非零$ f _ {\ rm nl} $。虽然来自光环偏置的大多数现有约束涉及星系分布的自动相关，但与物质密度探针的互相关为替代通道提供了较少的系统学通道。我们对仅使用互相关的局部原始非高斯性局限性提出了最强的大规模结构约束。我们使用由灰尘星系作为光环示踪剂和宇宙微波背景（CMB）镜头组成的宇宙红外背景（CIB）作为基础物质分布的探针，均来自\ textit {planck}数据。银河系灰尘是使用CIB大规模模式的关键挑战。重要的是，与CIB自动光谱相比，CIB与CMB镜头的互相关受银河粉尘的影响要小得多，CIB自动谱从银河粉尘中拾取了添加偏见。我们没有发现原始非高斯性的证据，可以找到$ -87 <f _ {\ rm nl} <19 $，带有高斯$σ（f _ {\ rm nl}）\ 41 $，假设halo质量功能的通用性。我们发现，来自Simons天文台和CMB-S4的未来CMB镜头数据可以分别达到23和20的$σ（f _ {\ rm nl}）$。这种分析的约束功率受到当前的银河灰尘清洁技术的限制，要求我们使用$ \ ell = 70 $的最小多极。如果通过改进的分析技术或外部数据克服了这一挑战，则可以通过互相关技术实现$σ（f _ {\ rm nl}）= 4 $的约束。更乐观的是，如果CIB自动光谱无尘到最大的尺度，则可以实现比$σ（f _ {\ rm nl}）= 2 $更好的约束。
Local non-Gaussianities in the initial conditions of the Universe, parameterized by $f_{\rm NL}$, induce a scale-dependence in the large-scale bias of halos in the late Universe. This effect is a promising path to constrain multi-field inflation theories that predict non-zero $f_{\rm NL}$. While most existing constraints from the halo bias involve auto-correlations of the galaxy distribution, cross-correlations with probes of the matter density provide an alternative channel with fewer systematics. We present the strongest large-scale structure constraint on local primordial non-Gaussianity that uses cross-correlations alone. We use the cosmic infrared background (CIB) consisting of dusty galaxies as a halo tracer and cosmic microwave background (CMB) lensing as a probe of the underlying matter distribution, both from \textit{Planck} data. Milky Way dust is a key challenge in using the large-scale modes of the CIB. Importantly, the cross-correlation of the CIB with CMB lensing is far less affected by Galactic dust compared to the CIB auto-spectrum, which picks up an additive bias from Galactic dust. We find no evidence for primordial non-Gaussianity and find $-87<f_{\rm NL}<19$ with a Gaussian $σ(f_{\rm NL})\approx 41$, assuming universality of the halo mass function. We find that future CMB lensing data from Simons Observatory and CMB-S4 could achieve $σ(f_{\rm NL})$ of 23 and 20 respectively. The constraining power of such an analysis is limited by current Galactic dust cleaning techniques, requiring us to use a minimum multipole of $\ell=70$. If this challenge is overcome with improved analysis techniques or external data, constraints as tight as $σ(f_{\rm NL})=4$ can be achieved through the cross-correlation technique. More optimistically, constraints better than $σ(f_{\rm NL})=2$ could be achieved if the CIB auto-spectrum is dust-free down to the largest scales.
