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Breakdown of rotational invariance of the primordial power spectrum manifests in the statistical anisotropy of the observed Cosmic Microwave Background (CMB) radiation. Hemispherical power asymmetry in the CMB may be caused due to a dipolar…

Cosmology and Nongalactic Astrophysics · Physics 2023-05-23 Md Ishaque Khan , Rajib Saha

The B-mode polarization of the cosmic microwave background (CMB) provides a unique window into tensor perturbations from inflationary gravitational waves. Survey effects complicate the estimation and description of the power spectrum on the…

Cosmology and Nongalactic Astrophysics · Physics 2016-09-28 Eric R. Switzer , Duncan J. Watts

We investigate a statistical anisotropy on the Cosmic Microwave Background (CMB) bispectrum, which can be generated from the primordial non-Gaussianity induced by quantum fluctuations of a vector field. We find new configurations in the…

Cosmology and Nongalactic Astrophysics · Physics 2011-12-03 Maresuke Shiraishi , Shuichiro Yokoyama

We use weighted mean and median statistics techniques to combine individual cosmic microwave background (CMB) anisotropy detections and determine binned, multipole-space, CMB anisotropy power spectra. The resultant power spectra are peaked.…

Tangled, primordial cosmic magnetic fields create small rotational velocity perturbations on the last scattering surface (LSS) of the cosmic microwave background radiation (CMBR). For fields which redshift to a present value of $B_0 =…

Astrophysics · Physics 2009-10-31 T. R. Seshadri , Kandaswamy Subramanian

Recently, BICEP2 has reported the large tensor-to-scalar ratio $r=0.2^{+0.07}_{-0.05}$ from the observation of the cosmic microwave background (CMB) B-mode at degree-scales. Since tensor modes induce not only CMB B-mode but also the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-19 Masahiro Kawasaki , Shuichiro Yokoyama

We evaluate our capability to constrain the abundance of primordial tensor perturbations in cosmologies with generalized expansion histories in the epoch of cosmic acceleration. Forthcoming satellite and sub-orbital experiments probing…

Cosmology and Nongalactic Astrophysics · Physics 2014-02-25 Claudia Antolini , Matteo Martinelli , Yabebal Fantaye , Carlo Baccigalupi

The characterization of the dust polarization foreground to the Cosmic Microwave Background (CMB) is a necessary step towards the detection of the B-mode signal associated with primordial gravitational waves. We present a method to simulate…

We constrain the contribution of tensor-mode perturbations with free $n_t$ in the models with dynamical dark energy with the barotropic equation of state using Planck-2015 data on CMB anisotropy, polarization and lensing, BICEP2/Keck Array…

Cosmology and Nongalactic Astrophysics · Physics 2017-06-15 O. Sergijenko

Beam asymmetries result in statistically-anisotropic cosmic microwave background (CMB) maps. Typically, they are studied for their effects on the CMB power spectrum, however they more closely mimic anisotropic effects such as gravitational…

Cosmology and Nongalactic Astrophysics · Physics 2010-10-05 Duncan Hanson , Antony Lewis , Anthony Challinor

The recently detected polarization of the cosmic microwave background (CMB) holds the potential for revealing the physics of inflation and gravitationally mapping the large-scale structure of the universe, if so called B-mode signals below…

Astrophysics · Physics 2011-05-12 Wayne Hu , Matthew M. Hedman , Matias Zaldarriaga

We develop the formalism necessary to study four-point functions of the cosmic microwave background (CMB) temperature and polarization fields. We determine the general form of CMB trispectra, with the constraints imposed by the assumption…

Astrophysics · Physics 2011-05-12 Takemi Okamoto , Wayne Hu

We calculate the detectability of the polarization of the cosmic microwave background (CMB) as a function of the sky coverage, angular resolution, and instrumental sensitivity for a hypothetical experiment. We consider the gradient…

Astrophysics · Physics 2009-10-31 Andrew H. Jaffe , Marc Kamionkowski , Limin Wang

In this thesis we investigate several aspects related to the theory of fluctuations in the Cosmic Microwave Background. We develop a new algorithm to calculate the angular power spectrum of the anisotropies which is two orders of magnitude…

Astrophysics · Physics 2007-05-23 Matias Zaldarriaga

Cosmic polarization rotation, which may result from parity-violating new physics or the presence of primordial magnetic fields, converts $E$-mode polarization of the cosmic microwave background (CMB) into $B$-mode polarization. Anisotropic…

Cosmology and Nongalactic Astrophysics · Physics 2022-01-20 Eric Guzman , Joel Meyers

We test the statistical isotropy (SI) of the $E$-mode polarization of the Cosmic Microwave Background (CMB) radiation observed by the Planck satellite using two statistics, namely, the $\alpha$ estimator that is derived from the contour…

Cosmology and Nongalactic Astrophysics · Physics 2021-06-11 Joby P. Kochappan , Aparajita Sen , Tuhin Ghosh , Pravabati Chingangbam , Soumen Basak

Quadratic methods with heuristic weighting (e.g. pseudo-C_l or correlation function methods) represent an efficient way to estimate power spectra of the cosmic microwave background (CMB) anisotropies and their polarization. We construct the…

Astrophysics · Physics 2008-11-26 Anthony Challinor , Gayoung Chon

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 exquisitely measured maps of fluctuations in the Cosmic Microwave Background (CMB) present the possibility to test the principle of Statistical Isotropy (SI) of the Universe through systematic observable measures for non-Statistical…

Cosmology and Nongalactic Astrophysics · Physics 2023-01-12 Dipanshu , Tarun Souradeep , Shriya Hirve

The aim of the present analysis is to improve the knowledge of the statistical properties of the Galactic diffuse synchrotron emission, which constrains sensitive CMB anisotropy measurements. We have analysed the new DRAO 1.4 GHz…

Astrophysics · Physics 2009-11-11 L. La Porta , C. Burigana , W. Reich , P. Reich