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Inflationary cosmologies predict Gaussian primordial fluctuations, but subsequent gravitational lensing of the CMB disturbs its Gaussianity. Knowledge of the specific signature of lensing is necessary to distinguish a lensed Gaussian sky…

Astrophysics · Physics 2007-05-23 Serge Winitzki

The cosmic microwave background (CMB) has non-Gaussian features in the temperature fluctuations. An anomalous cold spot surrounded with a hot ring, called the Cold Spot is one of such features. If a large underdence region (supervoid)…

Cosmology and Nongalactic Astrophysics · Physics 2018-02-14 Yuichi Higuchi , Kaiki Taro Inoue

We present a search for non-Gaussianity in the WMAP first-year data using the two-point correlation function of maxima and minima in the temperature map. We find evidence for non-Gaussianity on large scales, whose origin appears to be…

Astrophysics · Physics 2009-11-13 R. Tojeiro , P. G. Castro , A. F. Heavens , S. Gupta

We reassess the evidence that WMAP temperature maps contain a statistically significant "cold spot" by repeating the analysis using simple circular top-hat (disk) weights, as well as Gaussian weights of varying width. Contrary to previous…

Cosmology and Nongalactic Astrophysics · Physics 2010-05-18 Ray Zhang , Dragan Huterer

Since the very first observations, the Cosmic Microwave Background (CMB) has revealed on large-scales unexpected features known as anomalies, which challenge the standard $\Lambda$ cold dark matter ($\Lambda$CDM) cosmological model. One…

Cosmology and Nongalactic Astrophysics · Physics 2023-10-24 Giacomo Galloni , Mario Ballardini , Nicola Bartolo , Alessandro Gruppuso , Luca Pagano , Angelo Ricciardone

We provide evidence of the detection of a new non-Gaussian anomaly in the cosmic microwave background (CMB) radiation which has larger statistical significance than the Cold Spot (CS) anomaly and comparable size. This temperature anomaly is…

Cosmology and Nongalactic Astrophysics · Physics 2016-04-27 Antonio Enea Romano , Daniel Cornejo , Luis E. Campusano

We apply spherical needlets to the Wilkinson Microwave Anisotropy Probe 5-year cosmic microwave background (CMB) dataset, to search for imprints of non-isotropic features in the CMB sky. We use the needlets localization properties to…

We study statistical anisotropies generated in the observed two-point function of the cosmic microwave background (CMB) fluctuations if the primordial statistics are non-Gaussian. Focusing on the dipole modulations of the anisotropies, we…

Cosmology and Nongalactic Astrophysics · Physics 2018-07-17 Saroj Adhikari , Anne-Sylvie Deutsch , Sarah Shandera

This paper presents strong observational evidence of numerous previously unobserved anomalous circular spots, of significantly raised temperature, in the CMB sky. The spots have angular radii between 0.03 and 0.04 radians (i.e. angular…

Cosmology and Nongalactic Astrophysics · Physics 2022-08-10 Daniel An , Krzysztof A. Meissner , Pawel Nurowski , Roger Penrose

A new analysis of the CMB, using WMAP data, supports earlier indications of non-Gaussian features of concentric circles of low temperature variance. Conformal cyclic cosmology (CCC) predicts such features from supermassive black-hole…

Cosmology and Nongalactic Astrophysics · Physics 2018-11-06 V. G. Gurzadyan , R. Penrose

We apply a new method to measure primordial non-Gaussianity, using the cross-correlation between galaxy surveys and the CMB lensing signal to measure galaxy bias on very large scales, where local-type primordial non-Gaussianity predicts a…

Cosmology and Nongalactic Astrophysics · Physics 2014-06-06 Tommaso Giannantonio , Will J. Percival

The non-Gaussian cold spot detected in wavelet space in the WMAP 1-year data, is detected again in the coadded WMAP 3-year data at the same position (b = -57, l = 209) and size in the sky (around 10 degrees). The present analysis is based…

Astrophysics · Physics 2008-11-26 M. Cruz , L. Cayon , E. Martinez-Gonzalez , P. Vielva , J. Jin

We present a cosmic microwave background (CMB) lensing map produced from a linear combination of South Pole Telescope (SPT) and \emph{Planck} temperature data. The 150 GHz temperature data from the $2500\ {\rm deg}^{2}$ SPT-SZ survey is…

Upcoming cosmic microwave background (CMB) data can be used to explore harmonic 3-point functions that involve the B-mode component of the CMB polarization signal. We focus on bispectra describing the non-Gaussian correlation of the B-mode…

Cosmology and Nongalactic Astrophysics · Physics 2020-07-15 Adriaan J. Duivenvoorden , P. Daniel Meerburg , Katherine Freese

The first observations of the cosmic microwave background (CMB) from NASA's \emph{Wilkinson Microwave Anisotropy Probe} (WMAP) led to finding `alignment' anomalies not expected from fluctuations in the isotropic cosmological model. We study…

Cosmology and Nongalactic Astrophysics · Physics 2025-06-03 Sanjeet Kumar Patel , Pavan Kumar Aluri , John P. Ralston

Primordial black holes (PBHs) would induce non-Gaussianity in the cosmic microwave background (CMB) by sourcing recombination perturbations spatially modulated by relative velocities between PBHs and the baryons they accrete. The leading…

Cosmology and Nongalactic Astrophysics · Physics 2024-09-11 Trey W. Jensen , Yacine Ali-Haïmoud

We propose a "feature-scattering" mechanism to explain the cosmic microwave background cold spot seen from WMAP and Planck maps. If there are hidden features in the potential of multi-field inflation, the inflationary trajectory can be…

Cosmology and Nongalactic Astrophysics · Physics 2016-06-02 Yi Wang , Yin-Zhe Ma

We study the effect of primordial isocurvature perturbations on non-Gaussian properties of CMB temperature anisotropies. We consider generic forms of the non-linearity of isocurvature perturbations which can be applied to a wide range of…

We present an upgraded combined estimator, based on Minkowski Functionals and Neural Networks, with excellent performance in detecting primordial non-Gaussianity in simulated maps that also contain a weighted mixture of Galactic…

Cosmology and Nongalactic Astrophysics · Physics 2015-10-07 C. P. Novaes , A. Bernui , I. S. Ferreira , C. A. Wuensche

We present local extrema studies of two models that introduce a preferred direction into the observed cosmic microwave background (CMB) temperature field. In particular, we make a frequentist comparison of the one- and two-point statistics…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Zhen Hou , A. J. Banday , K. M. Gorski , N. E. Groeneboom , H. K. Eriksen