Light-cone mocks demonstrate that analytical corrections for survey-window and integral-constraint effects on PNG in galaxy power spectra lose accuracy below the equality scale and fail when PNG is present, enabling unbiased large-scale measurements.
Measuring line-of-sight dependent Fourier-space clustering using FFTs
4 Pith papers cite this work. Polarity classification is still indexing.
abstract
Observed galaxy clustering exhibits local transverse statistical isotropy around the line-of-sight (LOS). The variation of the LOS across a galaxy survey complicates the measurement of the observed clustering as a function of the angle to the LOS, as fast Fourier transforms (FFTs) based on Cartesian grids, cannot individually allow for this. Recent advances in methodology for calculating LOS-dependent clustering in Fourier space include the realization that power spectrum LOS-dependent moments can be constructed from sums over galaxies, based on approximating the LOS to each pair of galaxies by the LOS to one of them. We show that we can implement this method using multiple FFTs, each measuring the LOS-weighted clustering along different axes. The N log(N) nature of FFTs means that the computational speed-up is a factor of >1000 compared with summing over galaxies. This development should be beneficial for future projects such as DESI and Euclid which will provide an order of magnitude more galaxies than current surveys.
fields
astro-ph.CO 4representative citing papers
Optimal redshift weighting on eBOSS QSO full-shape data reduces uncertainties on H0 by 43.3%, σ8 by 19.7%, w0 by 20.5% and produces a bounded posterior on wa in the CPL model.
Introduces the observer power spectrum as a diagonal Fourier-space statistic for lightcone observables by transforming over observer positions rather than sources.
DESI DR1 full-shape galaxy clustering constrains Omega_m = 0.296 ± 0.010, H0 = 68.63 ± 0.79 km/s/Mpc, and sigma_8 = 0.841 ± 0.034, consistent with LambdaCDM and Planck.
citing papers explorer
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DESI 2024 V: Full-Shape Galaxy Clustering from Galaxies and Quasars
DESI DR1 full-shape galaxy clustering constrains Omega_m = 0.296 ± 0.010, H0 = 68.63 ± 0.79 km/s/Mpc, and sigma_8 = 0.841 ± 0.034, consistent with LambdaCDM and Planck.