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arXiv · 2212.04294

Cosmic tidal reconstruction in redshift space

Shi-Hui Zang·Hong-Ming Zhu·Marcel Schmittfull·Ue-Li Pen
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Abstract

The gravitational coupling between large- and small-scale density perturbations leads to anisotropic distortions to the local small-scale matter fluctuations. Such local anisotropic distortions can be used to reconstruct the large-scale matter distribution, known as tidal reconstruction. In this paper, we apply the tidal reconstruction methods to simulated galaxies in redshift space. We find that redshift-space distortions lead to anisotropic reconstruction results. While the reconstructed radial modes are more noisy mainly due to the small-scale velocity dispersion, the transverse modes are still reconstructed with high fidelity, well correlated with the original large-scale density modes. The bias of the reconstructed field at large scales shows a simple angular dependence which can be described by a form similar to the linear redshift-space distortion. The noise power spectrum is nearly isotropic and scale-independent on large scales. This makes the reconstructed tides field an ideal tracer for cosmic variance cancellation and multi-tracer analysis and has profound implications for future 21~cm intensity mapping surveys.

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Shi-Hui Zang, Hong-Ming Zhu, Marcel Schmittfull, Ue-Li Pen. 2022-12-08. Cosmic tidal reconstruction in redshift space. https://arxiv.org/abs/2212.04294

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