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Related papers: The CMB bispectrum from bouncing cosmologies

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Recent tentative findings of non-Gaussian structure in the COBE-DMR dataset have triggered renewed attention to candidate models from which such intrinsic signature could arise. In the framework of slow roll inflation with built-in non…

Astrophysics · Physics 2009-10-31 Alejandro Gangui , Jerome Martin

We investigate the dependence of cosmological parameters on the number count of peaks (local maxima and minima) in the cosmic microwave background (CMB) sky. The peak statistics contains the whole information of acoustic oscillations in the…

Astrophysics · Physics 2007-05-23 Toshifumi Futamase , Masahiro Takada

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 report a measurement of the E-mode polarization power spectrum of the cosmic microwave background (CMB) using 150 GHz data taken from July 2014 to December 2016 with the POLARBEAR experiment. We reach an effective polarization map noise…

We develop a new method to reconstruct the power spectrum of primordial curvature perturbations, $P(k)$, by using both the temperature and polarization spectra of the cosmic microwave background (CMB). We test this method using several mock…

Astrophysics · Physics 2009-10-09 Noriyuki Kogo , Misao Sasaki , Jun'ichi Yokoyama

Recently, BICEP2 measurements of the cosmic microwave background (CMB) $B$-mode polarization at degree angular scales has indicated the presence of tensor modes with a high tensor-to-scalar ratio of $r=0.2$ when assuming nearly…

High Energy Physics - Phenomenology · Physics 2015-06-22 Guo-Chin Liu , Kin-Wang Ng , I-Chin Wang

While the observed nearly scale-invariant initial power spectrum is regarded as one of the favorable evidence of the standard inflationary cosmology, precision observations of the Cosmic Microwave Background (CMB) anisotropies also suggest…

Cosmology and Nongalactic Astrophysics · Physics 2017-06-06 Koichiro Horiguchi , Kiyotomo Ichiki , Jun'ichi Yokoyama

We report the most complete analysis to date of observations of the Cosmic Microwave Background (CMB) obtained during the 1998 flight of BOOMERANG. We use two quite different methods to determine the angular power spectrum of the CMB in 20…

Recent results from BOOMERANG-98 and MAXIMA-1, taken together with COBE-DMR, provide consistent and high signal-to-noise measurements of the CMB power spectrum at spherical harmonic multipole bands over $2<\ell\lta800$. Analysis of the…

We analyze the spectrum of cosmic microwave background (CMB) anisotropies in the timescape cosmology: a potentially viable alternative to homogeneous isotropic cosmologies without dark energy. We exploit the fact that the timescape…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-18 M. Ahsan Nazer , David L. Wiltshire

The era of precision cosmology has allowed us to accurately determine many important cosmological parameters, in particular via the CMB. Confronting Loop Quantum Cosmology with these observations provides us with a powerful test of the…

General Relativity and Quantum Cosmology · Physics 2012-04-06 Ivan Agullo , Abhay Ashtekar , William Nelson

The damping of primordial perturbations at small scales gives rise to distortions of the cosmic microwave background (CMB). Here, the dependence of the distortion on the different types of cosmological initial conditions is explored,…

Cosmology and Nongalactic Astrophysics · Physics 2014-04-18 Jens Chluba , Daniel Grin

The low quadrupole of the cosmic microwave background (CMB), measured by COBE and confirmed by WMAP, has generated much discussion recently. We point out that the well-known correlation between temperature and polarization anisotropies of…

Astrophysics · Physics 2009-06-15 Olivier Doré , Gilbert P. Holder , Abraham Loeb

We use quadratic maximum-likelihood (QML) estimators to constrain models with Gaussian but statistically anisotropic Cosmic Microwave Background (CMB) fluctuations, using CMB maps with realistic sky-coverage and instrumental noise. This…

Cosmology and Nongalactic Astrophysics · Physics 2012-03-06 Duncan Hanson , Antony Lewis

Upcoming measurements of the small-scale primary cosmic microwave background (CMB) temperature and polarization power spectra ($TT$/$TE$/$EE$) are anticipated to yield transformative constraints on new physics, including the effective…

Cosmology and Nongalactic Astrophysics · Physics 2022-01-26 Fiona McCarthy , J. Colin Hill , Mathew S. Madhavacheril

Cosmological correlators encode rich information about physics at the Hubble scale and may exhibit characteristic oscillatory signals due to the exchange of massive particles. Although many 1-loop processes, especially those that break de…

High Energy Physics - Theory · Physics 2025-04-22 Zhehan Qin

Spectral distortions of the Cosmic Microwave Background (CMB) offer the possibility of probing processes which occurred during the evolution of our Universe going back up to Z$\simeq 10^7$. Unfortunately all the attempts so far carried out…

Instrumentation and Methods for Astrophysics · Physics 2017-02-22 Giorgio Sironi

We calculate the cosmic microwave background (CMB) bispectrum due to inhomogeneous reionization. We calculate all the terms that can contribute to the bispectrum that are products of first order terms on all scales in conformal Newtonian…

Cosmology and Nongalactic Astrophysics · Physics 2014-11-20 Rishi Khatri , Benjamin D. Wandelt

This brief article sums up the possible imprints of loop quantum gravity effects on the cosmological microwave background. We focus on semi-classical terms and show that "Big Bounce" corrections, together with the "pre Big Bounce" state,…

General Relativity and Quantum Cosmology · Physics 2018-12-19 Aurelien Barrau

In light of the recent observational data coming from the sky we have two significant directions in the field of theoretical cosmology recently. First, we are now able to make use of present observations, such as the Planck and BICEP2 data,…

High Energy Physics - Theory · Physics 2014-06-19 Yi-Fu Cai