论文标题
在存在21厘米强度映射前景的情况下测量超大标度效应
Measuring ultra-large scale effects in the presence of 21cm intensity mapping foregrounds
论文作者
论文摘要
\ textsc {hi}强度映射将提供宇宙中中性氢（\ textsc {hi}）的大规模分布的地图。这些是主要候选人，用于使用宇宙的大规模结构来限制原始非高斯性，并提供对爱因斯坦重力理论（GR）的进一步测试。但是\ textsc {hi}地图被前景污染，这可能比宇宙信号高几个数量级。在这里，我们量化了与残留前景的大规模效果（$ f _ {\ rm nl} $）的退化。我们得出的结论是，联合分析不能提供约束的灾难性退化，并提供了一个框架来确定在前景存在下大规模效应的边际错误。同样，我们得出的结论是，可以高精度测量前景的宏观特性。尽管如此，此类结果高度取决于前景的准确前向建模，这在灾难性地偏向宇宙参数，前景参数和大规模效应的最佳拟合价值上进行了错误。
\textsc{Hi} intensity mapping will provide maps of the large-scale distribution of neutral hydrogen (\textsc{Hi}) in the universe. These are prime candidates to be used to constrain primordial non-Gaussianity using the Large Scale Structure of the Universe as well as to provide further tests of Einstein's theory of Gravity (GR). But \textsc{Hi} maps are contaminated by foregrounds, which can be several orders of magnitude above the cosmological signal. Here we quantify how degenerated are the large-scale effects ($f_{\rm NL}$ and GR effects) with the residual foregrounds. We conclude that a joint analysis does not provide a catastrophic degradation of constraints and provides a framework to determine the marginal errors of large scale-effects in the presence of foregrounds. Similarly, we conclude that the macroscopical properties of the foregrounds can be measured with high precision. Notwithstanding, such results are highly dependent on accurate forward modelling of the foregrounds, which incorrectly done catastrophically bias the best fit values of cosmological parameters, foreground parameterisations, and large-scale effects.
