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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

A rigorous constraint analysis on cosmic inflation entails several probes which collectively survey an extensive range of energy scales. We complement the cosmic microwave background data with an updated compilation of the cosmic abundance…

Cosmology and Nongalactic Astrophysics · Physics 2019-04-23 Jurgen Mifsud , Carsten van de Bruck

Detection of the gravitational waves excited during inflation as quantum mechanical fluctuations is a key test of inflation and crucial to learning about the specifics of the inflationary model. We discuss the potential of Cosmic Background…

Astrophysics · Physics 2010-01-06 Michael S. Turner

We show that the cumulative CO emission from galaxies throughout cosmic history distorts the spectrum of the cosmic microwave background (CMB) at a level that is well above the detection limit of future instruments, such as the Primordial…

Cosmology and Nongalactic Astrophysics · Physics 2016-02-24 Natalie Mashian , Abraham Loeb , Amiel Sternberg

There are at least three cosmic backgrounds of primordial gravitational waves coming from inflation: those produced during inflation and associated with the stretching of quantum modes; those produced at the violent stage of preheating…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 Juan Garcia-Bellido

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

We emphasize that the estimation of cosmological parameters from cosmic microwave background (CMB) anisotropy data, such as the recent high resolution maps from BOOMERanG and MAXIMA-1, requires assumptions about the primordial spectra. The…

Astrophysics · Physics 2009-10-31 Jerome Martin , Alain Riazuelo , Dominik J. Schwarz

We present limits on the fraction of large angle microwave anisotropies which could come from tensor perturbations. We use the COBE results as well as smaller scale CMB observations, measurements of galaxy correlations, abundances of galaxy…

Astrophysics · Physics 2009-08-18 J. P. Zibin , Douglas Scott , Martin White

The inflationary paradigm is extremely successful regarding predictions of temperature anisotropies in the CMB. However, inflation also makes predictions for a CMB B-mode polarization, which has not been detected. Moreover, the standard…

General Relativity and Quantum Cosmology · Physics 2018-07-24 Gabriel León , Abhishek Majhi , Elias Okon , Daniel Sudarsky

Anisotropies in the cosmic microwave background radiation due to gravity waves are investigated. An initial spectrum of gravity waves may have been induced during an epoch of inflation. We study the propagation of such a spectrum in a…

Astrophysics · Physics 2008-02-03 Ruth Durrer , Tina Kahniashvili

In the early Universe matter can be described as a conformal invariant ultra-relativistic perfect fluid, which does not contribute, on classical level, to the evolution of the isotropic and homogeneous metric. If we suppose that there is…

High Energy Physics - Theory · Physics 2009-10-31 J. C. Fabris , A. M. Pelinson , I. L. Shapiro

We investigate whether non-adiabatic perturbations from inflation could produce an asymmetric distribution of temperature anisotropies on large angular scales in the cosmic microwave background (CMB). We use a generalised non-linear $\delta…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-23 Hooshyar Assadullahi , Hassan Firouzjahi , Mohammad Hossein Namjoo , David Wands

We reevaluate the predictions of inflation regarding primordial gravity waves, which should appear as B-modes in the CMB, in light of the fact that the standard inflationary paradigm is unable to account for the transition from an initially…

General Relativity and Quantum Cosmology · Physics 2017-11-22 Gabriel León , Abhishek Majhi , Elias Okon , Daniel Sudarsky

Within the context of supersymmetric hybrid inflation, we study a multiple-stage inflationary scenario that can generate a primordial spectrum of adiabatic density perturbations with a break at $k_b \simeq 0.05 h Mpc^{-1}$. The presence of…

High Energy Physics - Phenomenology · Physics 2007-05-23 Mairi Sakellariadou , Nikos Tetradis

The simplest realizations of the new inflationary scenario typically give rise to primordial density fluctuations which deviate logarithmically from the scale free Harrison - Zeldovich spectrum. We consider a number of such examples and, in…

High Energy Physics - Phenomenology · Physics 2011-05-12 R. K. Schaefer , Q. Shafi

I present a briefly summary of the current status of inflationary models versus topological defects scenarios, as the mechanisms which could have induced the initial density perturbations, which left an imprint on the cosmic microwave…

Astrophysics · Physics 2007-05-23 Mairi Sakellariadou

We derive power spectra of the scalar- and tensor-type structures generated in an inflation model based on a massive non-minimally coupled scalar field with the strong coupling assumption. We make analyses in both the original-frame and the…

Astrophysics · Physics 2009-12-30 J. Hwang , H. Noh

Loop quantum cosmology provides an efficient framework to study the evolution of the Universe beyond the classical Big Bang paradigm. Because of holonomy corrections, the singularity is replaced by a "bounce". The dynamics of the background…

General Relativity and Quantum Cosmology · Physics 2015-03-13 Jakub Mielczarek , Thomas Cailleteau , Julien Grain , Aurelien Barrau

In this short review, the predictions of inflation are presented and compared to the most recent measurements of the Cosmic Microwave Background (CMB) anisotropy. It is argued that inflation is compatible with these observations but that…

Astrophysics · Physics 2009-11-10 Jerome Martin

It is widely accepted that the primordial universe experienced a brief period of accelerated expansion called inflation. This scenario provides a plausible solution to the horizon and flatness problems. However, the particle physics…

General Relativity and Quantum Cosmology · Physics 2020-07-17 Sebastien Galtier , Jason Laurie , Sergey V. Nazarenko