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Related papers: Tensor Anisotropies in an Open Universe

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Cosmic microwave background (CMB) anisotropy may result from both scalar and tensor perturbations. For a sufficiently narrow range of angular scales, CMB perturbations can be characterized by four parameters. Results from the Cosmic…

Astrophysics · Physics 2009-10-22 Scott Dodelson , Lloyd Knox , Edward W. Kolb

Inflation provides a unified paradigm for understanding the isotropy of the cosmic microwave background (CMB), the flatness problem, and the origin of large-scale structure. Although the physics responsible for inflation is not yet well…

Astrophysics · Physics 2015-06-24 Marc Kamionkowski

Anisotropies in distortions to the frequency spectrum of the cosmic microwave background (CMB) can be created through spatially varying heating processes in the early Universe. For instance, the dissipation of small-scale acoustic modes…

Cosmology and Nongalactic Astrophysics · Physics 2017-01-25 Jens Chluba , Emanuela Dimastrogiovanni , Mustafa A. Amin , Marc Kamionkowski

COBE has provided us with a whole-sky map of the CBR anisotropies. However, even if the noise level is negligible when the four year COBE data are available, the cosmic variance will prevent us from obtaining information about the Gaussian…

Astrophysics · Physics 2016-08-30 Xiaochun Luo

The inflationary and pre-inflationary evolution of scalar modes of cosmological perturbations in a closed universe is analyzed for a loop quantum cosmology model with an inflationary regime consistent with the constraints on inflation…

General Relativity and Quantum Cosmology · Physics 2024-11-26 Lucas M. V. Montese , Nelson Yokomizo

The physics of the origin and evolution of CMB anisotropies is described. I explain the idea and status of cosmic parameter estimation and follow it up with critical comments on its dependence on model assumptions and initial conditions.

Astrophysics · Physics 2021-04-28 Ruth Durrer

We investigate the global texture model of structure formation in cosmogonies with non-zero cosmological constant for different values of the Hubble parameter. We find that the absence of significant acoustic peaks and little power on large…

Astrophysics · Physics 2009-10-31 Ruth Durrer , Martin Kunz , Alessandro Melchiorri

It is plausible that the scalar density perturbations are created by a relatively low scale model of inflation which predicts the CMB anisotropy and excites Standard Model baryon and cold dark matter, but negligible gravity waves.…

Astrophysics · Physics 2008-04-03 Rouzbeh Allahverdi , Anupam Mazumdar , Tuomas Multamaki

We investigate the cosmic variance of the skewness of the cosmic microwave background (CMB) anisotropies in an inflationary model which leads to the baryon isocurvature scenario for the cosmic structure formation. In this model, the baryon…

Astrophysics · Physics 2016-08-30 Kazuhiro Yamamoto , Misao Sasaki

The recent COBE measurement of anisotropies in the cosmic microwave background and the recent South Pole experiment of Gaier {\it et al.} offer an excellent opportunity to probe cosmological theories. We test a class of theories in which…

Astrophysics · Physics 2009-10-22 Scott Dodelson , Jay M. Jubas

We study signatures in the Cosmic Microwave Background (CMB) induced by the presence of strong spatial curvature prior to the epoch of inflation which generated our present universe. If inflation does not last sufficiently long to drive the…

Cosmology and Nongalactic Astrophysics · Physics 2010-02-02 Tim Clunan , David Seery

We study the effect of a stochastic background of gravitational waves on the gravitational lensing of the Cosmic Microwave Background (CMB) radiation. It has been shown that matter density inhomogeneities produce a smoothing of the acoustic…

Astrophysics · Physics 2016-08-30 Silvia Mollerach

We calculate the spectrum of gravitational waves generated during inflation in open $(\Omega _0<1)$ inflationary models. In such models an initial epoch of old inflation solves the horizon and flatness problems, and during this first epoch…

Astrophysics · Physics 2009-10-30 M. Bucher , J. D. Cohn

Observational Cosmology has indeed made very rapid progress in recent years. The ability to quantify the universe has largely improved due to observational constraints coming from structure formation Measurements of CMB anisotropy and, more…

Astrophysics · Physics 2009-11-11 Tarun Souradeep

We perform detailed calculations of cosmic microwave background (CMB) anisotropies in a CDM-dominated open universe with primordial adiabatic density perturbations for a variety of reionization histories. We show that to a great extent, the…

Astrophysics · Physics 2009-10-22 Marc Kamionkowski , David N. Spergel , Naoshi Sugiyama

We present a 1+3 covariant discussion of the contribution of gravitational waves to the anisotropy of the CMB in an almost-Friedmann-Robertson-Walker universe. Our discussion is based in the covariant approach to perturbations in cosmology,…

Astrophysics · Physics 2014-10-13 Anthony Challinor

Primordial gravitational waves generated during inflation lead to the B-mode polarization in the cosmic microwave background and a stochastic gravitational wave background in the Universe. We will explore the current constraint on the tilt…

Cosmology and Nongalactic Astrophysics · Physics 2025-03-28 Jun Li , Zu-Cheng Chen , Qing-Guo Huang

The temperature anisotropies and polarization of the cosmic microwave background (CMB) radiation provide a window back to the physics of the early universe. They encode the nature of the initial fluctuations and so can reveal much about the…

Astrophysics · Physics 2007-05-23 Anthony Challinor

The bispectrum of primordial curvature perturbations in the squeezed configuration, in which one wavenumber, $k_3$, is much smaller than the other two, $k_3\ll k_1\approx k_2$, plays a special role in constraining the physics of inflation.…

Cosmology and Nongalactic Astrophysics · Physics 2013-05-07 Maresuke Shiraishi , Eiichiro Komatsu , Marco Peloso , Neil Barnaby

Cosmic microwave background anisotropies provide a vast amount of cosmological information. Their full physical content and detailed structure can be understood in a simple and intuitive fashion through a systematic investigation of the…

Astrophysics · Physics 2009-10-28 Wayne Hu , Naoshi Sugiyama , Joseph Silk