Cleaned 3 Year<i>Wilkinson Microwave Anistropy Probe</i>Cosmic Microwave Background Map: Magnitude of the Quadrupole and Alignment of Large‐Scale Modes

Park, Chan-Gyung; Park, Changbom; Gott, J. Richard

doi:10.1086/513455

Cited by 58 publications

(63 citation statements)

References 37 publications

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“…They note that Chiang et al (2007) find that the lowest spherical harmonic modes in the ILC map are significantly contaminated by foregrounds. Park et al (2007) conclude that the residual foreground emission based on their own analysis is not statistically important to the large-scale modes of the CMB. Bennett et al (2011) also support the view that instead of early universe effects, the apparent lowmultipole alignment may be due to the integrated Sachs-Wolfe (ISW) effect associated the local ( < z 0.3) density fields.…”

Section: Introductionmentioning

confidence: 83%

“…The apparent planarlike arrangement of the octopole components was first noted by de Oliveira-Costa et al (2004), but revisited by many authors since then. In the analysis of Park et al (2007), the probability of observing such a planarity within the context of the standard model is over 18%, and therefore not statistically significant. It is comforting from the standpoint of the = R ct h universe that this feature appears to be present most of the time.…”

Section: Swmentioning

confidence: 97%

“…18.2 23 (Park et al 2007). Even with such a broadened uncertainty range, however, an alignment within q~ 18 23 should occur only~4.9% of the time, making it a marginally statistically significant anomaly within the standard model.…”

Section: The Cmb Angular Power Spectrum and Correlation Functionmentioning

confidence: 98%

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Cosmological Implications of the CMB Large-Scale Structure

Melia

2014

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The Wilkinson Microwave Anisotropy Probe (WMAP) and Planck may have uncovered several anomalies in the full cosmic microwave background (CMB) sky that could indicate possible new physics driving the growth of density fluctuations in the early universe. These include an unusually low power at the largest scales and an apparent alignment of the quadrupole and octopole moments. In a LCDM model where the CMB is described by a Gaussian Random Field, the quadrupole and octopole moments should be statistically independent. The emergence of these low probability features may simply be due to posterior selections from many such possible effects, whose occurrence would therefore not be as unlikely as one might naively infer. If this is not the case, however, and if these features are not due to effects such as foreground contamination, their combined statistical significance would be equal to the product of their individual significances. In the absence of such extraneous factors, and ignoring the biasing due to posterior selection, the missing large-angle correlations would have a probability as low as ∼0.1% and the low-l multipole alignment would be unlikely at the ∼4.9% level; under the least favorable conditions, their simultaneous observation in the context of the standard model could then be likely at only the ∼0.005% level. In this paper, we explore the possibility that these features are indeed anomalous, and show that the corresponding probability of CMB multipole alignment in the = R ct h universe would then be ∼7-10%, depending on the number of large-scale Sachs-Wolfe induced fluctuations. Since the low power at the largest spatial scales is reproduced in this cosmology without the need to invoke cosmic variance, the overall likelihood of observing both of these features in the CMB is ⩾7%, much more likely than in LCDM, if the anomalies are real. The key physical ingredient responsible for this difference is the existence in the former of a maximum fluctuation size at the time of recombination, which is absent in the latter because of inflation.

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Section: Introductionmentioning

confidence: 83%

Section: Swmentioning

confidence: 97%

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Cosmological Implications of the CMB Large-Scale Structure

Melia

2014

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“…It has been widely used for CMB estimation on WMAP data (Bennett et al 2003;Tegmark et al 2003;Eriksen et al 2004;Park et al 2007;Kim et al 2009;Samal et al 2009). A general description of the method can be found in .…”

Section: Internal Linear Combination Methodsmentioning

confidence: 99%

A comparison of algorithms for the construction of SZ cluster catalogues

Melin

Aghanim

Bartelmann

et al. 2012

A&A

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We evaluate the construction methodology of an all-sky catalogue of galaxy clusters detected through the Sunyaev-Zel'dovich (SZ) effect. We perform an extensive comparison of twelve algorithms applied to the same detailed simulations of the millimeter and submillimeter sky based on a Planck-like case. We present the results of this "SZ Challenge" in terms of catalogue completeness, purity, astrometric and photometric reconstruction. Our results provide a comparison of a representative sample of SZ detection algorithms and highlight important issues in their application. In our study case, we show that the exact expected number of clusters remains uncertain (about a thousand cluster candidates at |b| > 20 deg with 90% purity) and that it depends on the SZ model and on the detailed sky simulations, and on algorithmic implementation of the detection methods. We also estimate the astrometric precision of the cluster candidates which is found of the order of ∼2 arcmin on average, and the photometric uncertainty of about 30%, depending on flux.

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“…While there has been a recurring debate about the statistical significance of the quadrupole and the other outliers (notably, near the multipole moments 22 and 40) in the CMB angular power spectrum (see Refs. [6,7,8,9] and references therein), there has also been constant activity to understand possible underlying physical reasons for the outliers (see, for an inexhaustive list, Refs. [10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,27,28,29,30,31,32]).…”

Section: Introductionmentioning

confidence: 99%

Punctuated inflation and the low CMB multipoles

Jain

Chingangbam

Gong

et al. 2009

J. Cosmol. Astropart. Phys.

149

172

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Abstract. We investigate inflationary scenarios driven by a class of potentials which are similar in form to those that arise in certain minimal supersymmetric extensions of the standard model. We find that these potentials allow a brief period of departure from inflation sandwiched between two stages of slow roll inflation. We show that such a background behavior leads to a step like feature in the scalar power spectrum. We set the scales such that the drop in the power spectrum occurs at a length scale that corresponds to the Hubble radius today-a feature that seems necessary to explain the lower power observed in the quadrupole moment of the Cosmic Microwave Background (CMB) anisotropies. We perform a Markov Chain Monte Carlo analysis to determine the values of the model parameters that provide the best fit to the recent WMAP 5-year data for the CMB angular power spectrum. We find that an inflationary spectrum with a suppression of power at large scales that we obtain leads to a much better fit (with just one extra parameter, χ 2 eff improves by 6.62) of the observed data when compared to the best fit reference ΛCDM model with a featureless, power law, primordial spectrum.

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Cleaned 3 YearWilkinson Microwave Anistropy ProbeCosmic Microwave Background Map: Magnitude of the Quadrupole and Alignment of Large‐Scale Modes

Cited by 58 publications

References 37 publications

Cosmological Implications of the CMB Large-Scale Structure

Cosmological Implications of the CMB Large-Scale Structure

A comparison of algorithms for the construction of SZ cluster catalogues

Punctuated inflation and the low CMB multipoles

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