TY - JOUR

T1 - Fast estimators for redshift-space clustering

AU - Scoccimarro, Román

N1 - Publisher Copyright:
© 2015 American Physical Society.

PY - 2015/10/30

Y1 - 2015/10/30

N2 - Redshift-space distortions in galaxy surveys happen along the radial direction, breaking statistical translation invariance. We construct estimators for radial distortions that, using only fast fourier transforms (FFTs) of the overdensity field multipoles for a given survey geometry, compute the power spectrum monopole, quadrupole and hexadecapole, and generalize such estimators to the bispectrum. Using realistic mock catalogs we compare the signal to noise of two estimators for the power spectrum hexadecapole that require different number of FFTs and measure the bispectrum monopole, quadrupole and hexadecapole. The resulting algorithm is very efficient, e.g. the BOSS survey requires about 3 min for ℓ=0,2,4 power spectra for scales up to k=0.3 h Mpc-1 and about 15 additional min for ℓ=0,2,4 bispectra for all scales and triangle shapes up to k=0.2 h Mpc-1 on a single core. The speed of these estimators is essential as it makes possible for one to compute covariance matrices from large number of realizations of mock catalogs with realistic survey characteristics, and paves the way for improved constraints of gravity on cosmological scales, inflation and galaxy bias.

AB - Redshift-space distortions in galaxy surveys happen along the radial direction, breaking statistical translation invariance. We construct estimators for radial distortions that, using only fast fourier transforms (FFTs) of the overdensity field multipoles for a given survey geometry, compute the power spectrum monopole, quadrupole and hexadecapole, and generalize such estimators to the bispectrum. Using realistic mock catalogs we compare the signal to noise of two estimators for the power spectrum hexadecapole that require different number of FFTs and measure the bispectrum monopole, quadrupole and hexadecapole. The resulting algorithm is very efficient, e.g. the BOSS survey requires about 3 min for ℓ=0,2,4 power spectra for scales up to k=0.3 h Mpc-1 and about 15 additional min for ℓ=0,2,4 bispectra for all scales and triangle shapes up to k=0.2 h Mpc-1 on a single core. The speed of these estimators is essential as it makes possible for one to compute covariance matrices from large number of realizations of mock catalogs with realistic survey characteristics, and paves the way for improved constraints of gravity on cosmological scales, inflation and galaxy bias.

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U2 - 10.1103/PhysRevD.92.083532

DO - 10.1103/PhysRevD.92.083532

M3 - Article

AN - SCOPUS:84946944674

VL - 92

JO - Physical Review D - Particles, Fields, Gravitation and Cosmology

JF - Physical Review D - Particles, Fields, Gravitation and Cosmology

SN - 1550-7998

IS - 8

M1 - 083532

ER -