Non-Gaussianity and large-scale structure in a two-field inflationary model

Abstract

Single field inflationary models predict nearly Gaussian initial conditions and hence a detection of non-Gaussianity would be a signature of the more complex inflationary scenarios. In this paper we study the effect on the cosmic microwave background and on large scale structure from primordial non-Gaussianity in a two-field inflationary model in which both the inflaton and curvaton contribute to the density perturbations. We show that in addition to the previously described enhancement of the galaxy bias on large scales, this setup results in large-scale stochasticity. We provide joint constraints on the local non-Gaussianity parameter ${\tilde{f}}_{\mathrm{NL}}$ and the ratio $\xi$ of the amplitude of primordial perturbations due to the inflaton and curvaton using WMAP and SDSS data.

References in corpus (19)

• Wilkinson Microwave Anisotropy Probe (WMAP) Three Year Results: Implications for Cosmology
• Five-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Cosmological Interpretation
• Cosmological Constraints from the SDSS Luminous Red Galaxies
• Three Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Polarization Analysis
• Three-Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Temperature Analysis
• The imprints of primordial non-gaussianities on large-scale structure: scale dependent bias and abundance of virialized objects
• Clustering of High Redshift ($z\ge 2.9$) Quasars from the Sloan Digital Sky Survey
• Correlation of CMB with large-scale structure: I. ISW Tomography and Cosmological Implications
• Detection of primordial non-Gaussianity (fNL) in the WMAP 3-year data at above 99.5% confidence
• The bispectrum of galaxies from high-redshift galaxy surveys: primordial non-Gaussianity and non-linear galaxy bias
• Optimal limits on f_{NL}^{local} from WMAP 5-year data
• Primordial non-gaussianity, statistics of collapsed objects, and the Integrated Sachs-Wolfe effect
• Primordial non-Gaussianity: large-scale structure signature in the perturbative bias model
• Primordial non-Gaussianity, scale-dependent bias, and the bispectrum of galaxies
• Correlated isocurvature perturbations from mixed inflaton-curvaton decay
• Primordial Non-Gaussianity and the NRAO VLA Sky Survey
• Task Force on Cosmic Microwave Background Research
• Non-Gaussian halo assembly bias
• Limits on Isocurvature Perturbations from Non-Gaussianity in WMAP Temperature Anisotropies

Cited by in corpus (3)

• Scale-dependent non-Gaussianity probes inflationary physics
• A generalized local ansatz and its effect on halo bias
• Testing the Running of non-Gaussianity through the CMB mu-distortion and the Halo Bias