arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1909.05313astro-ph.CO
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分离的宇宙虚空偏向

Separate Universe Void Bias

Drew Jamieson, Marilena Loverde

摘要:

空洞已经成为宇宙学和大尺度结构的一种新的探测工具。这些密度极低的区域对宇宙学标准模型之外的物理学非常敏感,并且可以潜在地用作约束新物理学的试验场。我们提出了第一次测定的线性空隙偏差在不同的宇宙模拟测量。我们的方法进行了验证,通过比较单独的宇宙响应偏差与空洞的聚类偏差。我们发现这两种方法之间的良好协议的晕领域和下采样的暗物质领域中确定的空隙。对于由晕跟踪的空隙,我们确定了两种不同的贡献的偏见。第一个是由于用于识别空隙的底层晕场的偏差,而第二个我们归因于长波长密度扰动对空隙形成和膨胀的动力学影响。通过单独测量这些贡献,我们证明了它们的总和与总空隙偏差是一致的。我们还在模拟中测量了空洞的轮廓,并确定了它们各自的宇宙响应。这些可以解释为轮廓对宇宙背景密度的敏感性。

英文摘要:

Voids have emerged as a novel probe of cosmology and large-scale structure. These regions of extreme underdensity are sensitive to physics beyond the standard model of cosmology, and can potentially be used as a testing ground to constrain new physics. We present the first determination of the linear void bias measured in separate universe simulations. Our methods are validated by comparing the separate universe response bias with the clustering bias of voids. We find excellent agreement between the two methods for voids identified in the halo field and the down-sampled dark matter field. For voids traced by halos, we identify two different contributions to the bias. The first is due to the bias of the underlying halo field used to identify voids, while the second we attribute to the dynamical impact of long-wavelength density perturbations on void formation and expansion. By measuring these contributions individually, we demonstrate that their sum is consistent with the total void bias. We also measure the void profiles in our simulations, and determine their separate universe response. These can be interpreted as the sensitivity of the profiles to the background density of the Universe.

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