Large scale structure reconstruction with shortwavelength modes
Abstract
Large scale density modes are difficult to measure because they are sensitive to systematic observational errors in galaxy surveys, but we can study them indirectly by observing their impact on small scale perturbations. Cosmological perturbation theory predicts that secondorder density inhomogeneities are a convolution of a short and a longwavelength mode. This arises physically because small scale structures grow at different rates depending on the large scale environment in which they reside. This induces an off diagonal term in the twopoint statistics in Fourier space that we use as the basis for a quadratic estimator for the large scale field. We demonstrate that this quadratic estimator works well on an Nbody simulation of size (2.5 h^{1} Gpc )^{3} . In particular, the quadratic estimator successfully reconstructs the longwavelength modes using only smallscale information. This opens up novel opportunities to study structure on the largest observable scales.
 Publication:

Physical Review D
 Pub Date:
 April 2020
 DOI:
 10.1103/PhysRevD.101.083510
 arXiv:
 arXiv:2001.02780
 Bibcode:
 2020PhRvD.101h3510L
 Keywords:

 Astrophysics  Cosmology and Nongalactic Astrophysics
 EPrint:
 4 pages, 4 figures