Redshift-Space Distortions in Lagrangian Perturbation Theory

Dec 8, 2020
36 pages
Published in:
  • JCAP 03 (2021) 100
  • Published: Mar 29, 2021
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Abstract: (IOP)
We present the one-loop 2-point function of biased tracers in redshift space computed with Lagrangian perturbation theory, including a full resummation of both long-wavelength (infrared) displacements and associated velocities. The resulting model accurately predicts the power spectrum and correlation function of halos and mock galaxies from two different sets of N-body simulations at the percent level for quasi-linear scales, including the damping of the baryon acoustic oscillation signal due to the bulk motions of galaxies. We compare this full resummation with other, approximate, techniques including the moment expansion and Gaussian streaming model. We discuss infrared resummation in detail and compare our Lagrangian formulation with the Eulerian theory augmented by an infrared resummation based on splitting the input power spectrum into “wiggle” and “no-wiggle” components. We show that our model is able to recover unbiased cosmological parameters in mock data encompassing a volume much larger than what will be available to future galaxy surveys. We demonstrate how to efficiently compute the resulting expressions numerically, making available a fast Python code capable of rapidly computing these statistics in both configuration and Fourier space.
Note:
  • 37 pages, 10 figures, updated to match version accepted by JCAP
  • galaxy
  • perturbation theory
  • matter: power spectrum
  • correlation function
  • many-body problem
  • numerical calculations
  • data analysis method
  • Fourier transformation
  • baryon: oscillation: acoustic
  • moment