Forecasting cosmological constraints from the nonlinear halo density field with Zel'dovich-inspired transform
Abstract
The Zel'dovich-inspired (ZI) transform is a local nonlinear transform of the density field that can Gaussianize the late-time matter field and recover information from higher-order N-point correlation functions through its power spectrum, with the parameter η controlling the weighting of higher-order information. Using Fisher-matrix analyses of halo catalogs from the Quijote and Quijote-PNG simulations, we study the redshift-space monopole power spectrum of the ZI-transformed halo density field. The joint statistic PZI,0, constructed from three representative transforms with η=1, $10$, and +∞, yields substantially tighter constraints than the conventional halo power spectrum Ph,0 on standard cosmological parameters, the summed neutrino mass, and primordial non-Gaussianity amplitudes, while outperforming the marked power spectrum for many parameters. We further calibrate a scale-dependent noise correction for the ZI power spectrum, with an effective noise amplitude that depends on wavenumber, and find that the correction further tightens the constraints. In particular, the noise-corrected PZI,0 improves the constraints on fNLequil, fNLortho, Mν, and ns by factors of $5.6$, $5.5$, $5.2$, and $5.8$, respectively, relative to Ph,0. These results demonstrate the potential of ZI power spectra as a complement to standard two-point statistics for extracting nonlinear cosmological information. Our forecasts may be conservative because the halo catalogs have substantially lower number densities than those expected from forthcoming galaxy surveys.
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BibTeX
@misc{zhou2026forecasting,
title = {{Forecasting cosmological constraints from the nonlinear halo density field with Zel'dovich-inspired transform}},
author = {Yu Zhou and Yun Wang and Haozhe Zhang and Matteo Peron and Shiyu Deng and Yu Yu and Xin Zhang},
howpublished = {arXiv},
year = {2026},
month = oct,
doi = {10.48550/arxiv.2610.04486},
eprint = {2610.04486},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2610.04486},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Forecasting cosmological constraints from the nonlinear halo density field with Zel'dovich-inspired transform
AU - Yu Zhou
AU - Yun Wang
AU - Haozhe Zhang
AU - Matteo Peron
AU - Shiyu Deng
AU - Yu Yu
AU - Xin Zhang
PY - 2026
DA - 2026/10/03
PB - arXiv
DO - 10.48550/arxiv.2610.04486
UR - https://arxiv.org/abs/2610.04486
AB - The Zel'dovich-inspired (ZI) transform is a local nonlinear transform of the density field that can Gaussianize the late-time matter field and recover information from higher-order N-point correlation functions through its power spectrum, with the parameter η controlling the weighting of higher-order information. Using Fisher-matrix analyses of halo catalogs from the Quijote and Quijote-PNG simulations, we study the redshift-space monopole power spectrum of the ZI-transformed halo density field. The joint statistic P_ZI,0, constructed from three representative transforms with η=1, $10$, and +∞, yields substantially tighter constraints than the conventional halo power spectrum P_h,0 on standard cosmological parameters, the summed neutrino mass, and primordial non-Gaussianity amplitudes, while outperforming the marked power spectrum for many parameters. We further calibrate a scale-dependent noise correction for the ZI power spectrum, with an effective noise amplitude that depends on wavenumber, and find that the correction further tightens the constraints. In particular, the noise-corrected P_ZI,0 improves the constraints on f_NL^equil, f_NL^ortho, M_ν, and n_s by factors of $5.6$, $5.5$, $5.2$, and $5.8$, respectively, relative to P_h,0. These results demonstrate the potential of ZI power spectra as a complement to standard two-point statistics for extracting nonlinear cosmological information. Our forecasts may be conservative because the halo catalogs have substantially lower number densities than those expected from forthcoming galaxy surveys.
ER -