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We re-analyse the cosmic microwave background (CMB) Cold Spot (CS) anomaly with particular focus on understanding the bias a mask (contaminated by Galactic and point sources) may introduce. We measure the coldest spot, found by applying the…

Cosmology and Nongalactic Astrophysics · Physics 2017-10-10 Krishna Naidoo , Aurélien Benoit-Lévy , Ofer Lahav

The divergence of the momentum density field of the large scale structure generates a secondary anisotropy contribution to the Cosmic Microwave Background (CMB). While the effect is best described as a non-linear extension to the well-known…

Astrophysics · Physics 2009-11-13 Asantha Cooray , Naoki Seto

A remarkable similarity between the large-scale non-Gaussian pattern of cosmic microwave background (CMB) temperatures obtained by Wilkinson Microwave Anisotropy Probe (WMAP) mission and the distribution feature of observation numbers is…

Cosmology and Nongalactic Astrophysics · Physics 2009-09-01 Ti-Pei Li , Hao Liu , Li-Ming Song , Shao-Lin Xiong , Jian-Yin Nie

We study two different methods to test Gaussianity in CMB maps. One of them is based on the partition function and the other on the morphology of hot and cold spots. The partition function contains information on all the moments and scales,…

We present a new method for constructing maps of the secondary temperature fluctuations imprinted on the cosmic microwave background (CMB) radiation by photons propagating through the evolving cosmic gravitational potential. Large…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 Yan-Chuan Cai , Shaun Cole , Adrian Jenkins , Carlos S. Frenk

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 present a new method based on the N-point probability distribution (pdf) to study non-Gaussianity in cosmic microwave background (CMB) maps. Likelihood and Bayesian estimation are applied to a local non-linear perturbed model up to third…

Astrophysics · Physics 2015-05-13 P. Vielva , J. L. Sanz

Statistical Isotropy of the Cosmic Microwave Background (CMB) radiation has been studied and debated extensively in recent years. Under this assumption, the hot spots and cold spots of the CMB are expected to be uniformly distributed over a…

Cosmology and Nongalactic Astrophysics · Physics 2022-11-14 Md Ishaque Khan , Rajib Saha

In a concordant $\Lambda$ Cold Dark Matter ($\Lambda$CDM) model, large-angle Cosmic Microwave Background (CMB) temperature anisotropy due to linear perturbations in the local universe is not negligible. We explore a possible role of an…

Cosmology and Nongalactic Astrophysics · Physics 2012-04-09 Kaiki Taro Inoue

Temperature maps of the Cosmic Microwave Background (CMB) radiation, as those obtained by the Wilkinson Microwave Anisotropy Probe (WMAP), provide one of the most precise data sets to test fundamental hypotheses of modern cosmology. One of…

Astrophysics · Physics 2009-11-13 Armando Bernui , Constantino Tsallis , Thyrso Villela

We search the BOOMERanG maps of the anisotropy of the Cosmic Microwave Background (CMB) for deviations from gaussianity. In this paper we focus on analysis techniques in pixel-space, and compute skewness, kurtosis and Minkowski functionals…

A new map of the sky representing the degree of randomness in the cosmic microwave background (CMB) temperature has been obtained. The map based on estimation of the Kolmogorov stochasticity parameter clearly distinguishes the contribution…

Higher Criticism is a recently developed statistic for non-Gaussian detection, proposed in Donoho & Jin 2004. We find that Higher Criticism is useful for two purposes. First, Higher Criticism has competitive detection power, and…

Astrophysics · Physics 2008-11-26 L. Cayon , J. Jin , A. Treaster

A detection or nondetection of primordial non-Gaussianity by using the cosmic microwave background radiation (CMB) offers a way of discriminating inflationary scenarios and testing alternative models of the early universe. This has…

Cosmology and Nongalactic Astrophysics · Physics 2012-02-15 A. Bernui , M. J. Reboucas , A. F. F. Teixeira

We investigate the performance of spherical wavelets in discriminating between standard inflationary models (Gaussian) and non-Gaussian models. For the later we consider small perturbations of the Gaussian model in which an artificially…

Astrophysics · Physics 2009-11-07 E. Martinez-Gonzalez , J. E. Gallegos , F. Argueso , L. Cayon , J. L. Sanz

We describe and discuss the application of Gumbel statistics, which model extreme events, to WMAP 5-year measurements of the cosmic microwave background. We find that temperature extrema of the CMB are well modelled by the Gumbel formalism…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-01 Gatis Mikelsons , Joseph Silk , Joe Zuntz

We continue investigation of the hidden plane-mirror symmetry in the distribution of excursion sets in cosmic microwave background (CMB) temperature anisotropy maps, previously noticed in the three-year data of the Wilkinson microwave…

Understanding the statistical properties of synchrotron emission from our Galaxy is valuable from the perspective of observations targeting signals of cosmological origin, as well as for understanding physical processes in our Galaxy. In…

Cosmology and Nongalactic Astrophysics · Physics 2024-01-18 Fazlu Rahman , Pravabati Chingangbam , Tuhin Ghosh

The presence of non--Gaussian features in the Cosmic Microwave Background (CMB) radiation maps represents one of the most long--awaited clues in the search for the actual structure of the primordial radiation, still needing confirmation.…

Astrophysics · Physics 2009-10-22 Alejandro Gangui

We study inhomogeneities in the distribution of the excursion sets in the Cosmic Microwave Background (CMB) temperature maps obtained by the three years survey of the Wilkinson Microwave Anisotropy Probe (WMAP). At temperature thresholds…

Astrophysics · Physics 2009-06-23 V. G. Gurzadyan , A. A. Starobinsky , A. L. Kashin , H. Khachatryan , G. Yegorian