Second-order matter fluctuations via higher-order galaxy correlators

Abstract

We provide a formula for extracting the value of the rms of the linear matter fluctuations on a scale R directly from redshift surveys data. It allows to constrain the real-space amplitude of sigma_R without requiring any modeling of the nature and power spectrum of the matter distribution. Furthermore, the formalism is completely insensitive to the character of the bias function, namely its eventual scale or non-linear dependence. By contrasting measurements of sigma_R with predictions from linear perturbation theory, one can test for eventual departures from the standard description of gravity on large cosmological scales. The proposed estimator exploits the information contained in the 1-point moments and 2-point correlators of the matter and galaxy density fields, and it can be applied on cosmic scales where linear and semi-linear perturbative approximations of the evolution of matter overdensities offer a satisfactory description of the full underlying theory. We implement the test with N-body simulations to quantify potential systematics and successfully show that we are able to recover the present day value of sigma_8 `hidden' in the simulation. We also design a consistency check to gauge the soundness of the results inferred when the formalism is applied to real (as opposed to simulated) data. We expect that this approach will provide a sensitive probe of the clustering of matter when applied to future large redshift survey such as BigBOSS and EUCLID.

24 pages, 5 figures, accepted for publication in MNRAS. Typos corrected, references added, to match the version published by MNRAS

References in corpus (10)

• Cosmological Constraints from the SDSS Luminous Red Galaxies
• A test of the nature of cosmic acceleration using galaxy redshift distortions
• Are f(R) dark energy models cosmologically viable ?
• A discriminating probe of gravity at cosmological scales
• Confirmation of general relativity on large scales from weak lensing and galaxy velocities
• Observational Tests of Modified Gravity
• The assembly bias of dark matter haloes to higher orders
• How to Falsify the GR+LambdaCDM Model with Galaxy Redshift Surveys
• The VIMOS VLT Deep Survey: Testing the gravitational instability paradigm at z ~ 1
• A Null Test of the Metric Nature of the Cosmic Acceleration

Cited by in corpus (11)

• Large-Scale Galaxy Bias
• Near optimal bispectrum estimators for large-scale structure
• Measuring the growth of matter fluctuations with third-order galaxy correlations
• The Scale of Cosmic Isotropy
• Cosmological constraints from galaxy clustering in the presence of massive neutrinos
• The VIMOS Public Extragalactic Redshift Survey (VIPERS): ${\Omega }_{{\mathrm{m}}_0}$ from the galaxy clustering ratio measured at $z\sim 1$
• Non-local bias contribution to third-order galaxy correlations
• Cosmological tests of modified gravity: constraints on $F(R)$ theories from the galaxy clustering ratio
• A question of separation: disentangling tracer bias and gravitational nonlinearity with counts-in-cells statistics
• The VIMOS Public Extragalactic Redshift Survey (VIPERS): On the correct recovery of the count-in-cell probability distribution function
• Determination of the abundance of cosmic matter via the cell count moments of the galaxy distribution (1)