The EFT of Large Scale Structures at All Redshifts: Analytical Predictions for Lensing

Mar 5, 2015
39 pages
Published in:
  • JCAP 04 (2016) 033
  • Published: Apr 18, 2016
e-Print:

Citations per year

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Abstract: (IOP)
We study the prediction of the Effective Field Theory of Large Scale Structures (EFTofLSS) for the matter power spectrum at different redshifts. In previous work, we found that the two-loop prediction can match the nonlinear power spectrum measured from N-body simulations at redshift zero within approximately 2% up to k~ 0.6 h Mpc(-1) after fixing a single free parameter, the so-called 'speed of sound'. We determine the time evolution of this parameter by matching the EFTofLSS prediction to simulation output at different redshifts, and find that it is well-described by a fitting function that only includes one additional parameter. After the two free parameters are fixed, the prediction agrees with nonlinear data within approximately 2% up to at least k~ 1 h Mpc(-1) at z≥ 1, and also within approximately 5% up to k~ 1.2 h Mpc(-1) at z=1 and k~ 2.3 h Mpc(-1) at z=3, a major improvement with respect to other perturbative techniques. We also develop an accurate way to estimate where the EFTofLSS predictions at different loop orders should fail, based on the sizes of the next-order terms that are neglected, and find agreement with the actual comparisons to data. Finally, we use our matter power spectrum results to perform analytical calculations of lensing potential power spectra corresponding to both CMB and galaxy lensing. This opens the door to future direct applications of the EFTofLSS to observations of gravitational clustering on cosmic scales.
Note:
  • 40 pages, 20 figures. v2: JCAP published version, improved theory-error estimates, extended explanations and minor corrections
  • effective field theory
  • matter: power spectrum
  • power spectrum: nonlinear
  • many-body problem
  • numerical calculations
  • velocity: acoustic
  • perturbation theory: higher-order
  • gravitation: lens
  • cosmic background radiation
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