Berkeley Center for Cosmological Physics, University of California, Berkeley, California 94720, USA.
Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, California 93720, USA.
Phys Rev Lett. 2018 Sep 7;121(10):101301. doi: 10.1103/PhysRevLett.121.101301.
We develop a new method to constrain primordial non-Gaussianities of the local kind using unclustered tracers of the large scale structure. We show that, in the limit of low noise, zero bias tracers yield large improvement over standard methods, mostly due to vanishing sampling variance. We propose a simple technique to construct such a tracer, using environmental information obtained from the original sample and validate our method with N-body simulations. Our results indicate that σ_{f_{NL}^{loc}}≃1 can be reached using only information on a single tracer of sufficiently high number density.
我们开发了一种新方法，通过利用大尺度结构的无聚类示踪剂来限制局部形式的原始非高斯性。我们表明，在低噪声极限下，零偏示踪剂比标准方法有很大的改进，主要是由于采样方差为零。我们提出了一种简单的技术来构建这样的示踪剂，使用从原始样本中获得的环境信息，并通过 N 体模拟验证了我们的方法。我们的结果表明，仅使用足够高密度的单个示踪剂的信息，就可以达到 σ_{f_{NL}^{loc}}≃1。
