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The most promising avenue for detecting primordial gravitational waves from cosmic inflation is through measurements of degree-scale CMB $B$-mode polarisation. This approach must face the challenge posed by gravitational lensing of the CMB,…

Cosmology and Nongalactic Astrophysics · Physics 2022-07-20 Antón Baleato Lizancos , Anthony Challinor , Blake D. Sherwin , Toshiya Namikawa

We consider the hypothesis that nonlocal, omnidirectional, causally-coherent quantum entanglement of inflationary horizons may account for some well-known measured anomalies of Cosmic Microwave Background (CMB) anisotropy on large angular…

General Relativity and Quantum Cosmology · Physics 2022-02-16 Craig Hogan , Stephan S. Meyer

Extra radiation injection after neutrino decoupling in the early Universe contributes to the effective number of neutrino species that can be constrained by the cosmic microwave background (CMB). However, any effective neutrino number…

Cosmology and Nongalactic Astrophysics · Physics 2025-10-07 Shao-Ping Li , Jens Chluba

Acoustic peaks in the Cosmic Microwave Background (CMB) temperature spectrum as observed by the Planck satellite appear to be smoother than our expectation from the standard model lensing effect. This anomalous effect can be also mimicked…

Cosmology and Nongalactic Astrophysics · Physics 2022-09-07 Dhiraj Kumar Hazra , Akhil Antony , Arman Shafieloo

In a recent publication, we used the data from WMAP and SDSS to constrain the primordial perturbations and to predict the B-mode polarization sourced by cosmic string networks. We have been alerted by A. Slosar to the existence of errors in…

Astrophysics · Physics 2007-05-23 Levon Pogosian , Ira Wasserman , Mark Wyman

Spectral distortions of the cosmic microwave background (CMB) may become a powerful probe of primordial perturbations at small scales. Existing studies of spectral distortions focus almost exclusively on primordial scalar metric…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-22 Jens Chluba , Liang Dai , Daniel Grin , Mustafa A. Amin , Marc Kamionkowski

The B-mode polarization spectrum of the Cosmic Microwave Background (CMB) may be the smoking gun of not only the primordial tensor mode but also of the primordial vector mode. If there exist nonzero vector-mode metric perturbations in the…

Cosmology and Nongalactic Astrophysics · Physics 2014-10-03 Shohei Saga , Maresuke Shiraishi , Kiyotomo Ichiki

One of the most intriguing hints of a departure from the standard cosmological model is a large-scale dipolar power asymmetry in the cosmic microwave background (CMB). If not a statistical fluke, its origins must lie in the modulation of…

Cosmology and Nongalactic Astrophysics · Physics 2017-03-23 J. P. Zibin , D. Contreras

Gravitational waves from inflation induce polarization patterns in the cosmic microwave background (CMB). It is known that there are only two types of non-Gaussianities of the gravitaional waves in the most general scalar field theories…

Cosmology and Nongalactic Astrophysics · Physics 2018-08-01 Hiroaki W. H. Tahara , Jun'ichi Yokoyama

Measurements of CMB anisotropy and, more recently, polarization have played a very important role allowing precise determination of various parameters of the `standard' cosmological model. The expectation of the paradigm of inflation and…

Astrophysics · Physics 2008-11-26 Tarun Souradeep

Given observations of B-mode polarization power spectrum of the cosmic microwave background (CMB), we can reconstruct power spectra of primordial tensor modes from the early Universe without assuming their functional form such as a…

Cosmology and Nongalactic Astrophysics · Physics 2018-06-20 Takashi Hiramatsu , Eiichiro Komatsu , Masashi Hazumi , Misao Sasaki

Possible existence of the primordial magnetic fields has affected the structure formation of the universe. In this paper it is shown that the initial conditions for density perturbations with magnetic fields derived in previous works are…

Cosmology and Nongalactic Astrophysics · Physics 2009-03-20 Kazuhiko Kojima , Kiyotomo Ichiki

The detection of B-modes in the Cosmic Microwave Background (CMB) polarization by the BICEP2 experiment, if interpreted as evidence for a primordial gravitational wave background, has enormous ramifications for cosmology and physics. It is…

Cosmology and Nongalactic Astrophysics · Physics 2016-11-29 Nora Elisa Chisari , Cora Dvorkin , Fabian Schmidt

Motivated by the fact that cosmological perturbations of inflationary quantum origin were born Gaussian, the search for non-Gaussianities in the cosmic microwave background (CMB) anisotropies is considered as the privileged probe of…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-17 Christophe Ringeval

String models can produce successful inflationary scenarios in the context of brane collisions and in many of these models cosmic strings may also be produced. In scenarios such as KKLMMT the string contribution is naturally predicted to be…

Astrophysics · Physics 2009-11-11 Uros Seljak , Anze Slosar

Fluctuations in the cosmic microwave background (CMB) temperature are being studied with ever increasing precision. Two competing types of theories might describe the origins of these fluctuations: ``inflation'' and ``defects''. Here we…

Astrophysics · Physics 2010-04-08 Andreas Albrecht , David Coulson , Pedro Ferreira , Joao Magueijo

A complete numerical calculation of the temperature anisotropies and the polarization of the cosmic microwave background (CMB) is presented for a non zero cross correlation of a stochastic magnetic field with the primordial curvature…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-15 Kerstin E. Kunze

We investigate the power spectrum of the distortion of Cosmic Microwave Background (CMB) due to the decay of the primordial magnetic fields. It is known that there are two-types of the CMB distortions, so-called \mu- and y-types and we find…

Cosmology and Nongalactic Astrophysics · Physics 2014-03-12 Koichi Miyamoto , Toyokazu Sekiguchi , Hiroyuki Tashiro , Shuichiro Yokoyama

It is possible to explain the discrepancy (tension) between the local measurement of the cosmological parameter $H_0$ (the Hubble constant) and its value derived from the Planck-mission measurements of the Cosmic Microwave Background (CMB)…

Cosmology and Nongalactic Astrophysics · Physics 2023-01-25 Vladimir Yershov

We investigate a possibility of constraining statistical anisotropies of the primordial tensor perturbations by using future observations for the Cosmic Microwave Background (CMB) B-mode polarization. By parameterizing a…

Cosmology and Nongalactic Astrophysics · Physics 2018-10-24 Takashi Hiramatsu , Shuichiro Yokoyama , Tomohiro Fujita , Ippei Obata