The Cold Spot as a Large Void: Rees-Sciama effect on CMB Power Spectrum and Bispectrum

Abstract

The detection of a "Cold Spot" in the CMB sky could be explained by the presence of an anomalously large spherical underdense region (with radius of a few hundreds Mpc/h) located between us and the Last Scattering Surface. Modeling such an underdensity with an LTB metric, we investigate whether it could produce significant signals on the CMB power spectrum and bispectrum, via the Rees-Sciama effect. We find that this leads to a bump on the power spectrum, that corresponds to an O(5%-25%) correction at multipoles 5 < l < 50; in the cosmological fits, this would modify the χ^2 by an amount of order unity. We also find that the signal should be visible in the bispectrum coefficients with a signal-to-noise S/N ~ O (1-10), localized at 10 < l < 40. Such a signal would lead to an overestimation of the primordial f_{NL} by an amount Δf_{NL} ~ 1 for WMAP and by Δf_{NL} ~ 0.1 for Planck.

v1: 17 pages, 8 figures; v2: published version (improvements in the text, comments added), 17 pages, 8 figures

References in corpus (30)

• Non-Gaussian features of primordial fluctuations in single field inflationary models
• Non-Gaussianity from Inflation: Theory and Observations
• Acoustic Signatures in the Primary Microwave Background Bispectrum
• Asymmetries in the CMB anisotropy field
• First Year Wilkinson Microwave Anisotropy Probe (WMAP) Observations: Tests of Gaussianity
• Second-Order Cosmological Perturbations from Inflation
• Relativistic second-order perturbations of the Einstein-de Sitter Universe
• Hemispherical power asymmetry in the three-year Wilkinson Microwave Anisotropy Probe sky maps
• Detection of primordial non-Gaussianity (fNL) in the WMAP 3-year data at above 99.5% confidence
• The non-Gaussian Cold Spot in the 3-year WMAP data
• The Microwave Background Bispectrum, Paper II: A Probe of the Low Redshift Universe
• The non-Gaussian Cold Spot in WMAP: significance, morphology and foreground contribution
• Extragalactic Radio Sources and the WMAP Cold Spot
• Local Voids as the Origin of Large-angle Cosmic Microwave Background Anomalies I
• A Cosmic Microwave Background feature consistent with a cosmic texture
• The Microwave Background Bispectrum, Paper I: Basic Formalism
• "Swiss-Cheese" Inhomogeneous Cosmology & the Dark Energy Problem
• Nonlinear Structure Formation and "Apparent" Acceleration: an Investigation
• Local Voids as the Origin of Large-angle Cosmic Microwave Background Anomalies: The Effect of a Cosmological Constant
• Detection of the ISW effect and corresponding dark energy constraints
• Detection of the ISW effect and corresponding dark energy constraints made with directional spherical wavelets
• Cosmic Microwave Background anisotropies from second order gravitational perturbations
• Impact of Secondary non-Gaussianities on the Search for Primordial Non-Gaussianity with CMB Maps
• Contribution to the Three--Point Function of the Cosmic Microwave Background from the Rees--Sciama Effect
• Second-order gravitational effects of local inhomogeneities on CMB anisotropies and non-Gaussian signatures
• Effect of Void Network on CMB Anisotropy
• "Graceful" Old Inflation
• Mysteries on Universe's Largest Observable Scales
• Can Inflation solve the Hierarchy Problem?
• On the Rees-Sciama effect: maps and statistics

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• Full-sky map of the ISW and Rees-Sciama effect from Gpc simulations
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• Swiss Cheese and a Cheesy CMB
• Supervoids in the WISE-2MASS catalogue imprinting Cold Spots in the Cosmic Microwave Background
• Perceiving the equation of state of Dark Energy while living in a Cold Spot
• A Theory of a Spot
• Do the observational data favor a local void?
• Uncertainty on w from large-scale structure
• Studying the precision of ray tracing techniques with Szekeres models
• Evidence of Quasi-linear Super-Structures in the Cosmic Microwave Background and Galaxy Distribution
• Could multiple voids explain the Cosmic Microwave Background Cold Spot anomaly?
• The Cold Spot as a Large Void: Lensing Effect on CMB Two and Three Point Correlation Functions
• Spatial and temporal tuning in void models for acceleration
• CMB polarization as a probe of the anomalous nature of the Cold Spot
• CMB seen through random Swiss Cheese
• On the origin of the Cold Spot
• Dynamical evolutin of quintessence dark energy in collapsing dark matter halos
• The CMB cold spot under the lens: ruling out a supervoid interpretation
• Detecting the Cold Spot as a Void with the Non-Diagonal Two-Point Function