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Related papers: The CMB bispectrum from bouncing cosmologies

200 papers

The role of cosmic microwave background (CMB) polarisation data in constraining the presence of primordial isocurvature modes is examined. While the MAP satellite mission will be unable to simultaneously constrain isocurvature modes and…

Astrophysics · Physics 2009-10-31 M Bucher , K Moodley , N Turok

The Planck satellite is right now measuring with unprecedented accuracy the primary Background CMB anisotropies. The Standard Model of the Universe (including inflation) provides the context to analyze the CMB and other data. The Planck…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-18 C. Burigana , C. Destri , H. J. de Vega , A. Gruppuso , N. Mandolesi , P. Natoli , N. G. Sanchez

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

Physical models for the hemispherical power asymmetry in the cosmic microwave background (CMB) reported by the Planck Collaboration must satisfy CMB constraints to the homogeneity of the Universe and quasar constraints to power asymmetries.…

Cosmology and Nongalactic Astrophysics · Physics 2013-06-26 Liang Dai , Donghui Jeong , Marc Kamionkowski , Jens Chluba

We study the angular bispectrum of local type arising from the (possibly correlated) combination of a primordial adiabatic mode with an isocurvature one. Generically, this bispectrum can be decomposed into six elementary bispectra. We…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-04 David Langlois , Bartjan van Tent

The most convincing confirmation that the B-mode polarization signal detected at degree scales by BICEP2 is due to the Cosmic Microwave Background (CMB) would be the measurement of its large-scale counterpart. We assess the requirements for…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-22 A. Bonaldi , S. Ricciardi , M. L. Brown

We develop a method to constrain non-isotropic features of Cosmic Microwave Background (CMB) polarization, of a type expected to arise in some models describing quantum gravity effects on light propagation. We describe the expected…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Giulia Gubitosi , Marina Migliaccio , Luca Pagano , Giovanni Amelino-Camelia , Alessandro Melchiorri , Paolo Natoli , Gianluca Polenta

The cosmic microwave background (CMB) temperature bispectrum is currently the most precise tool for constraining primordial non-Gaussianity (NG). The Planck temperature data tightly constrain the amplitude of local-type NG: $f_{\rm NL}^{\rm…

Cosmology and Nongalactic Astrophysics · Physics 2018-11-06 J. Colin Hill

Primordial B-mode detection is one of the main goals of current and future cosmic microwave background (CMB) experiments. However, the weak B-mode signal is overshadowed by several Galactic polarized emissions, such as thermal dust emission…

Cosmology and Nongalactic Astrophysics · Physics 2023-04-18 Ye-Peng Yan , Guo-Jian Wang , Si-Yu Li , Jun-Qing Xia

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 2011-01-17 Pranjal Trivedi , Kandaswamy Subramanian , T. R. Seshadri

We discuss the large scale polarization of the cosmic microwave background induced by the anisotropy of the spatial geometry of our universe. Assuming an eccentricity at decoupling of about $0.64 10^{-2}$, we find an average large scale…

Cosmology and Nongalactic Astrophysics · Physics 2010-03-18 Paolo Cea

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

If the primordial bispectrum is sufficiently large then the CMB hemispherical asymmetry may be explained by a large-scale mode of exceptional amplitude which perturbs the zeta two-point function. We extend previous calculations, which were…

Cosmology and Nongalactic Astrophysics · Physics 2016-06-27 Christian T. Byrnes , Donough Regan , David Seery , Ewan R. M. Tarrant

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

The CMB is perhaps the cleanest cosmological observable. Given a cosmology model, the angular spectrum of the CMB can be computed to percent accuracy. On the observational side, as far as we know, there is little that stands in the way…

Astrophysics · Physics 2007-05-23 L. A. Page

The imprint of neutrino oscillations on the Cosmic Microwave Background (CMB) anisotropy and polarization power spectra is evaluated in a $\Lambda$CHDM model with two active neutrino flavors, consistent with the structure formation models…

Astrophysics · Physics 2011-05-23 L. Popa , C. Burigana , F. Finelli , N. Mandolesi

Probing primordial curvature perturbations on small scales, beyond those accessible using cosmic microwave background (CMB) primary anisotropies and Lyman-$\alpha$ forest data, remains a major open challenge. Current constraints on the…

High Energy Physics - Phenomenology · Physics 2025-09-03 Aurora Ireland , Kuver Sinha , Tao Xu

We present a new independent pipeline for the CMB bispectrum estimation of primordial non-Gaussianity and release a public code for constraining bispectrum shapes of interest based on the Planck 2018 temperature and polarization data. The…

Cosmology and Nongalactic Astrophysics · Physics 2023-10-06 Wuhyun Sohn , James R. Fergusson , E. P. S. Shellard

The lecture is devoted to the comparison of a few models of cosmic recombination kinetics with recent CMB anisotropy data and to corresponding predictions for the upcoming PLANCK mission. The influence of additional sources of ionized…

Astrophysics · Physics 2007-05-23 Pavel D. Naselsky

The current enthusiam to measure fluctuations in the CMB power spectrum at angular scales between 0.1 and 1 degree is largely motivated by the expectation that CMB determinations of cosmological parameters will be of unprecedented…

Astrophysics · Physics 2007-05-23 C. H. Lineweaver