We investigate the prospects of measuring the cosmic magnification effect by cross-correlating neutral hydrogen intensity mapping (HI IM) maps with background optical galaxies. We forecast the signal-to-noise ratio for HI IM data from SKA1-MID and HIRAX, combined with LSST photometric galaxy samples. We find that, thanks to their different resolutions, SKA1-MID and HIRAX are highly complementary in such an analysis. We predict that SKA1-MID can achieve a detection with a signal-to-noise ratio of $\sim 15$ on a multipole range of $\ell \lesssim 200$, while HIRAX can reach a signal-to-noise ratio of $\sim 50$ on $200 < \ell < 2000$. We conclude that measurements of the cosmic magnification signal will be possible on a wide redshift range with foreground HI intensity maps up to $z \lesssim 2$, while optimal results are obtained when $0.6 \lesssim z \lesssim 1.3$. Finally, we perform a signal to noise analysis that shows how these measurements can constrain the HI parameters across a wide redshift range.

中文翻译：

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使用 Hi 强度映射进行宇宙放大测量的前景

我们通过将中性氢强度映射（HI IM）图与背景光学星系互相关来研究测量宇宙放大效应的前景。我们预测了来自 SKA1-MID 和 HIRAX 的 HI IM 数据的信噪比，并结合了 LSST 光度测量星系样本。我们发现，由于它们的分辨率不同，SKA1-MID 和 HIRAX 在这样的分析中具有很强的互补性。我们预测 SKA1-MID 可以在 $\ell\lesssim 200$ 的多极范围内实现信噪比 $\sim 15$ 的检测，而 HIRAX 可以达到 $\sim 15$ 的信噪比\sim 50$ 对 $200 < \ell < 2000$。我们得出结论，宇宙放大信号的测量可以在宽红移范围内进行，前景 HI 强度图高达 $z \lesssim 2 $，而在 $0 时获得最佳结果。6 \lesssim z \lesssim 1.3$。最后，我们进行了信噪比分析，展示了这些测量如何在宽红移范围内约束 HI 参数。