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In single-field, slow-roll inflationary models, scalar and tensorial (Gaussian) perturbations are both characterized by a zero mean and a non-zero variance. In position space, the corresponding variance of those fields diverges in the…

General Relativity and Quantum Cosmology · Physics 2014-11-20 I. Agullo , J. Navarro-Salas , Gonzalo J. Olmo , Leonard Parker

I highlight the remarkable advances in the past few years in CMB research on total primary anisotropies, in determining the power spectrum, deriving cosmological parameters from it, and more generally lending credence to the basic…

Astrophysics · Physics 2007-05-23 J. Richard Bond

Observations of the Cosmic Microwave Background (CMB) B-mode polarisation provide a unique probe of inflationary physics. Extracting a reliable constraint on the tensor-to-scalar ratio $r$ nonetheless demands stringent suppression of…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-14 Aliza Mustafa , Alessandro Carones , Nicoletta Krachmalnicoff , Marina Migliaccio , Carlo Baccigalupi

Upcoming cosmic microwave background (CMB) data can be used to explore harmonic 3-point functions that involve the B-mode component of the CMB polarization signal. We focus on bispectra describing the non-Gaussian correlation of the B-mode…

Cosmology and Nongalactic Astrophysics · Physics 2020-07-15 Adriaan J. Duivenvoorden , P. Daniel Meerburg , Katherine Freese

Models of spontaneous wave function collapse modify the linear Schr\"{o}dinger equation of standard Quantum Mechanics by adding stochastic non-linear terms to it. The aim of such models is to describe the quantum (linear) nature of…

Cosmology and Nongalactic Astrophysics · Physics 2012-09-14 Kinjalk Lochan , Suratna Das , Angelo Bassi

The paradigm of \Lambda CDM cosmology works impressively well and with the concept of inflation it explains the universe after the time of decoupling. However there are still a few concerns; after much effort there is no detection of dark…

General Physics · Physics 2017-03-22 B. Vlahovic

The BICEP2 collaboration reported recently a B-mode polarization of the cosmic microwave background (CMB) radiation inconsistent with the null hypothesis at a significance of > 5 {\sigma}. This result has been often interpreted as a…

General Physics · Physics 2014-08-28 Luis Gonzalez-Mestres

I discuss constraints on the power spectrum of primordial tensor perturbations from a combination of Cosmic Microwave Background (CMB) measurements and the gravitational wave direct detection experiments LIGO/Virgo and DECIGO. There are two…

Cosmology and Nongalactic Astrophysics · Physics 2021-07-07 William H. Kinney

We investigate the impact of a hypothesized delayed initiation of inflation, characterized by a cutoff k_min to the primordial power spectrum in the cosmic microwave background (CMB). This cutoff affects both the scalar and tensor spectra,…

Cosmology and Nongalactic Astrophysics · Physics 2025-07-28 Jingwei Liu , Fulvio Melia

Inflation gives rise to a nearly scale-invariant spectrum of tensor perturbations (gravitational waves), their contribution to the Cosmic Background Radiation (CBR) anisotropy depends upon the present cosmological parameters as well as…

Astrophysics · Physics 2014-10-13 Michael S. Turner , Yun Wang

We constrain the shape of the primordial power spectrum using recent measurements of the cosmic microwave background (CMB) from the Wilkinson Microwave Anisotropy Probe (WMAP) 7-year data and other high-resolution CMB experiments. We also…

Cosmology and Nongalactic Astrophysics · Physics 2012-06-27 J. Alberto Vazquez , A. N. Lasenby , M. Bridges , M. P. Hobson

One of the main problems for extracting the Cosmic Microwave Background (CMB) from submm/mm observations is to correct for the Galactic components, mainly synchrotron, free - free and thermal dust emission with the required accuracy.…

Cosmology and Nongalactic Astrophysics · Physics 2018-10-17 H. U. Nørgaard-Nielsen

[Abridged] The polarization of the CMB is widely recognized as a potential source of information about primordial gravitational waves. The gravitational wave contribution can be separated from the dominant CMB polarization created by…

Astrophysics · Physics 2009-11-10 Christopher M. Hirata , Abraham Loeb , Niayesh Afshordi

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

Following Kamionkowski (2008), a quadratic estimator of the rotation of the plane of polarization of the CMB is constructed. This statistic can estimate a spatially varying rotation angle. We use this estimator to quantify the prospects of…

Cosmology and Nongalactic Astrophysics · Physics 2009-08-03 Amit P. S. Yadav , Rahul Biswas , Meng Su , Matias Zaldarriaga

We develop a comprehensive cosmological framework based on the principle that our universe originated as a three-dimensional spatial configuration governed purely by energy functionals, with time emerging dynamically through quantum loop…

General Physics · Physics 2026-01-13 Farrukh A. Chishtie

From CMB polarization data alone we reconstruct the CMB lensing power spectrum, comparable in overall constraining power to previous temperature-based reconstructions, and an unlensed E-mode power spectrum. The observations, taken in 2019…

It has been shown that a three-point correlation function of tensor perturbations from a bounce model in general relativity with a minimally-coupled scalar field is highly suppressed, and the resultant three-point function of cosmic…

Cosmology and Nongalactic Astrophysics · Physics 2024-04-23 Shingo Akama , Giorgio Orlando , Paola C. M. Delgado

CMB photons travel from the last scattering surface, when the primary CMB has been generated, along the surface of the light cone to us. During their travel, they are affected by many secondary effects such as the integrated Sachs-Wolfe…

Cosmology and Nongalactic Astrophysics · Physics 2019-03-11 Mario Ballardini

In this article, we do a thorough investigation of the competency of the forthcoming Cosmic Microwave Background (CMB) and Galaxy surveys in probing the features in the primordial power spectrum. Primordial features are specific…

Cosmology and Nongalactic Astrophysics · Physics 2022-11-01 Debabrata Chandra , Supratik Pal
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