Cosmic Tidal Reconstruction with Halo Fields

TL;DR

This paper introduces a new 3D tidal reconstruction algorithm that leverages full tidal shear data to improve large-scale matter mode recovery from halo fields, aiding cosmological studies.

Contribution

A novel tidal reconstruction method utilizing complete 3D tidal shear information, enhancing large-scale mode recovery over previous approaches.

Findings

Reconstructed large-scale density correlates well with original matter field.

Improved recovery of large-scale modes compared to previous methods.

Implications for 21cm cosmology and primordial non-Gaussianity constraints.

Abstract

The gravitational coupling between large-scale perturbations and small-scale perturbations leads to anisotropic distortions of the small-scale matter distribution. The measured local small-scale power spectrum can thus be used to infer the large-scale matter distribution. In this paper, we present a new tidal reconstruction algorithm for reconstructing large-scale modes using the full three-dimensional tidal shear information. We apply it to simulated dark matter halo fields and the reconstructed large-scale density field correlates well with the original matter density field on large scales, improving upon the previous tidal reconstruction method which only uses two transverse shear fields. This has profound implications for recovering lost 21~cm radial modes due to foreground subtraction and constraining primordial non-Gaussianity using the multi-tracer method with future cosmological surveys.