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The cosmic microwave background (CMB) contains perturbations that are close to Gaussian and isotropic. This means that its information content, in the sense of the ability to constrain cosmological models, is closely related to the number…

Cosmology and Nongalactic Astrophysics · Physics 2016-07-06 Douglas Scott , Dagoberto Contreras , Ali Narimani , Yin-Zhe Ma

We present results from a first test of the Gaussianity of degree-scale cosmic microwave background (CMB) anisotropy. We investigate Gaussianity of the CMB anisotropy by studying the topology of CMB anisotropy maps from the QMAP and…

Astrophysics · Physics 2009-10-07 Chan-Gyung Park , Changbom Park , Bharat Ratra , Max Tegmark

Searching for and charactering the non-Gaussianity (NG) of a given field has been a vital task in many fields of science, because we expect the consequences of different physical processes to carry different statistical properties. Here we…

Astrophysics · Physics 2007-05-23 Jiun-Huei Proty Wu

The cosmic microwave background (CMB) provides us with our most direct observational window to the early universe. Observations of the temperature and polarization anisotropies in the CMB have played a critical role in defining the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 Anthony Challinor

The CMB anisotropy depends sensitively upon the slope and amplitude of primordial density and gravitational wave fluctuations, the baryon density, the Hubble constant, the cosmological constant, the ionization history, {\it etc.} We report…

Astrophysics · Physics 2009-09-25 J. Richard Bond , Richard L. Davis , Paul J. Steinhardt

A new method for estimating the angular power spectrum C_l from cosmic microwave background (CMB) maps is presented, which has the following desirable properties: (1) It is unbeatable in the sense that no other method can measure C_l with…

Astrophysics · Physics 2009-10-07 Max Tegmark

We present an efficient method to compute CMB anisotropies in non-flat universes. First we derive the Boltzmann equation for cosmic microwave background temperature and polarization fluctuations produced by scalar perturbations in a general…

Astrophysics · Physics 2009-06-16 Matias Zaldarriaga , Uros Seljak , Edmund Bertschinger

Recent measurements of the Cosmic Microwave Background Anisotropy have provided evidence for the presence of oscillations in the angular power spectrum. These oscillations are a wonderful confirmation of the standard cosmological scenario…

Astrophysics · Physics 2007-05-23 Alessandro Melchiorri

We review Maxwell's multipole vectors, and elucidate some of their mathematical properties, with emphasis on the application of this tool to the cosmic microwave background (CMB). In particular, for a completely random function on the…

Astrophysics · Physics 2009-11-13 Mark R. Dennis , Kate Land

We devise a fast and optimal estimator for the amplitude of the bispectrum of clustered Infrared (IR) point-sources. We show how this estimator can account for the cases of partial sky coverage and inhomogeneous noise. Expected detection…

Cosmology and Nongalactic Astrophysics · Physics 2014-09-24 F. Lacasa , N. Aghanim

The COBE satellite's maps of the cosmic microwave background (CMB) anisotropy do not have the resolution to discriminate between theories of cosmic structure formation based on inflation, and those based on field ordering following a…

High Energy Physics - Phenomenology · Physics 2009-09-25 David Coulson , Ue-Li Pen , Neil Turok

Future low-noise cosmic microwave background (CMB) lensing measurements from e.g., CMB-S4 will be polarization dominated, rather than temperature dominated. In this new regime, statistically optimal lensing reconstructions outperform the…

Cosmology and Nongalactic Astrophysics · Physics 2025-05-20 Frank J. Qu , Marius Millea , Emmanuel Schaan

We present a Gaussianity test of the cosmic microwave background (CMB) polarization by analyzing the statistics of unpolarized points in the sky, classified into three distinct types: saddles, comets, and beaks. This classification of…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-01 K. O. Parfenov , D. I. Novikov , A. O. Mihalchenko

Primordial magnetic fields lead to non-Gaussian signals in the Cosmic Microwave Background (CMB) even at the lowest order, as magnetic stresses, and the temperature anisotropy they induce, depend quadratically on the magnetic field. In…

Cosmology and Nongalactic Astrophysics · Physics 2009-09-03 T. R. Seshadri , Kandaswamy Subramanian

We present a new source separation method which maximizes the likelihood of a model of noisy mixtures of stationary, possibly Gaussian, independent components. The method has been devised to address the problem of imaging CMB anisotropies.…

We present an implementation of an optimal CMB trispectrum estimator which accounts for anisotropic noise and incomplete sky coverage. We use a general separable mode expansion which can and has been applied to constrain both primordial and…

Cosmology and Nongalactic Astrophysics · Physics 2010-12-30 J. R. Fergusson , D. M. Regan , E. P. S. Shellard

In the first part of this work, I review the theoretical framework of cosmological perturbation theory necessary to understand the generation and evolution of cosmic microwave background (CMB) anisotropies. Using analytical and numerical…

Astrophysics · Physics 2009-09-29 Roberto Trotta

The last years have been an exciting period for the field of the Cosmic Microwave Background (CMB) research. With recent CMB balloon-borne and ground-based experiments we are entering a new era of 'precision' cosmology that enables us to…

Astrophysics · Physics 2007-05-23 Alessandro Melchiorri

Accurate measurements of the Cosmic Microwave Background (CMB) anisotropy call for high precision and reliability of the in-flight calibration. For extended surveys the CMB dipole provides an excellent calibration source at frequencies…

Astrophysics · Physics 2009-11-10 B. Cappellini , D. Maino , G. Albetti , P. Platania , R. Paladini , A. Mennella , M. Bersanelli

We estimate the magnitude of the bias due to non-Gaussian extragalactic foregrounds on the optimal reconstruction of the cosmic microwave background (CMB) lensing potential and temperature power spectra. The reconstruction is performed…

Cosmology and Nongalactic Astrophysics · Physics 2025-07-25 M. Doohan , M. Millea , S. Raghunathan , F. Ge , L. Knox , K. Prabhu , C. L. Reichardt , W. L. K. Wu