Large-scale bias and efficient generation of initial conditions for nonlocal primordial non-Gaussianity

By R. Scoccimarro, L. Hui, Marc Manera, Kwan Chuen Chan. 2011

145 citations recorded by the source corpus.

We study the scale-dependence of halo bias in generic (non-local) primordial non-Gaussian (PNG) initial conditions of the type motivated by inflation, parametrized by an arbitrary quadratic kernel. We first show how to generate non-local PNG initial conditions with minimal overhead compared to local PNG models for a general class of primordial bispectra that can be written as linear combinations of separable templates. We run cosmological simulations for the local, and non-local equilateral and orthogonal models and present results on the scale-dependence of halo bias. We also derive a general formula for the Fourier-space bias using the peak-background split (PBS) in the context of the excursion set approach to halos and discuss the difference and similarities with the known corresponding result from local bias models. Our PBS bias formula generalizes previous results in the literature to include non-Markovian effects and non-universality of the mass function and are in better agreement with measurements in numerical simulations than previous results for a variety of halo masses, redshifts and halo definitions. We also derive for the first time quadratic bias results for arbitrary non-local PNG, and show that non-linear bias loops give small corrections at large-scales. The resulting well-behaved perturbation theory paves the way to constrain non-local PNG from measurements of the power spectrum and bispectrum in galaxy redshift surveys.

Subfields: Astronomy and Astrophysics, Nuclear and High Energy Physics

View Paper: https://www.semanticscholar.org/paper/6e52bb4be39c871d12e614699dc001d9da492ec1

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

In Nuclear and High Energy Physics

Citations in the corpus

Matter power spectrum and the challenge of percent accuracy (2015, methodology): “The initial conditions are based on second order Lagrangian perturbation theory (2LPT), generated at redshift 50 with a modified version of the IC code from Scoccimarro et al. (2012).”
The clustering of galaxies in the SDSS-III DR9 Baryon Oscillation Spectroscopic Survey: constraints on primordial non-Gaussianity (2012, background): “Primordial non-Gaussianity can also be measured from the bispectrum of cosmic microwave background (CMB) anisotropies (see, e.g., Bartolo et al. 2004; Komatsu 2010 and references therein) and, in principle, galaxies (see e.g. Sefusatti & Komatsu 2007; Scoccimarro et al. 2012).”
The clustering of galaxies in the SDSS-III Baryon Oscillation Spectroscopic Survey: RSD measurement from the power spectrum and bispectrum of the DR12 BOSS galaxies (2016, background): “…of the primordial non-Gaussian signal, for example through fNL (Gangui et al. 1994; Fry & Scherrer 1994; Verde et al. 2000; Scoccimarro et al. 2004; Sefusatti & Komatsu 2007; Sefusatti 2009; Sefusatti et al. 2010, 2012; Scoccimarro et al. 2012; Tellarini et al. 2015, 2016; Welling et al. 2016).”