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We investigate the primordial power spectrum of the density perturbations based on the assumption that spacetime is noncommutative in the early stage of inflation. Due to the spacetime noncommutativity, the primordial power spectrum can…

Cosmology and Nongalactic Astrophysics · Physics 2010-12-02 Khamphee Karwan

We assay how inflationary models whose properties are dominated by the dynamics of a single scalar field are constrained by cosmic microwave background (CMB) data from the Wilkinson Microwave Anisotropy Probe (WMAP). We classify…

High Energy Physics - Phenomenology · Physics 2009-09-15 V. Barger , Hye-Sung Lee , Danny Marfatia

We perform a Bayesian analysis to study possible features in the primordial inflationary power spectrum of scalar perturbations. In particular, we analyse the possibility of detecting the imprint of these primordial features in the…

Cosmology and Nongalactic Astrophysics · Physics 2016-08-24 Micol Benetti , Jailson S. Alcaniz

Distortions of the Cosmic Microwave Background energy spectrum of the $\mu$ type are sensitive to the primordial power spectrum through the dissipation of curvature perturbations on scales $k\simeq 50$ - $10^4\,\mathrm{Mpc}^{-1}$. Their…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-19 Giovanni Cabass , Enrico Pajer , Drian van der Woude

The simplest inflationary models predict a primordial power spectrum (PPS) of the curvature fluctuations that can be described by a power-law function that is nearly scale-invariant. It has been shown, however, that the low-multipole…

Cosmology and Nongalactic Astrophysics · Physics 2016-05-25 Eleonora Di Valentino , Stefano Gariazzo , Martina Gerbino , Elena Giusarma , Olga Mena

The Cosmic Microwave Background (CMB) anisotropy power on the largest angular scales observed both by WMAP and COBE DMR appears to be lower than the one predicted by the standard model of cosmology with almost scale free primordial…

Astrophysics · Physics 2009-09-29 Carlo R. Contaldi , Marco Peloso , Lev Kofman , Andrei Linde

We propose a straightforward and model independent methodology for characterizing the sensitivity of CMB and other experiments to wiggles, irregularities, and features in the primordial power spectrum. Assuming that the primordial…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-11 Christopher Gauthier , Martin Bucher

The predictive power of cosmic inflation hinges on the existence of a conserved quantity at very large scales, called the primordial curvature perturbation, which is therefore insensitive to the details of reheating and the physics of the…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-11 Matteo Braglia , Lucas Pinol

We consider Cosmic Microwave Background constraints on inflation models for which the primordial power spectrum is a mixture of perturbations generated by inflaton fluctuations and fluctuations in a curvaton field. If future experiments do…

Cosmology and Nongalactic Astrophysics · Physics 2013-09-10 William H. Kinney , Azadeh Moradinezhad Dizgah , Antonio Riotto

We examine cosmological perturbations in a dynamical theory of inflation in which an Abelian gauge field couples directly to the inflaton, breaking conformal invariance. When the coupling between the gauge field and the inflaton takes a…

Cosmology and Nongalactic Astrophysics · Physics 2010-10-13 Timothy R. Dulaney , Moira I. Gresham

Features in the primordial power spectrum have been suggested as an explanation for glitches in the angular power spectrum of temperature anisotropies measured by the WMAP satellite. However, these glitches might just as well be artifacts…

Cosmology and Nongalactic Astrophysics · Physics 2010-05-28 Jan Hamann , Arman Shafieloo , Tarun Souradeep

The recently relased \emph{Planck} data, emphasize that the background geometry of inflation is not pure de Sitter, but from the slow variation of Hubble parameter during the inflationary era, it can be quasi-de Sitter. This motivates us to…

Cosmology and Nongalactic Astrophysics · Physics 2018-04-09 Hossein Moshafi , Ata Sojasi , Ebrahim Yusofi , Majid Mohsenzadeh

Future cosmic microwave background polarization experiments will search for evidence of primordial tensor modes at large angular scales, in the multipole range $4 \leq \ell \leq 50.$ Because in that range there is some mild evidence of…

Cosmology and Nongalactic Astrophysics · Physics 2017-04-26 Gonzalo A. Palma , Bastian Pradenas , Walter Riquelme , Spyros Sypsas

Standard inflation with one scalar field produces primordial perturbations with a nearly flat ('Harrison-Zeldovich') power spectrum. Here we consider first, a double inflation spectrum, and second, a massive scalar field with an interaction…

Astrophysics · Physics 2016-08-30 Lutz V. Semig , Volker Mueller

Inflationary cosmology provides a natural mechanism for the generation of primordial perturbations which seed the formation of observed cosmic structure and lead to specific signals of anisotropy in the cosmic microwave background…

Astrophysics · Physics 2011-07-19 Salman Habib , Andreas Heinen , Katrin Heitmann , Gerard Jungman

The hemispherical power asymmetry in the cosmic microwave background may be explained by the modulation of some primordial cosmological parameter, such as the sound speed of the inflaton. This modulation can be achieved by the perturbation…

Cosmology and Nongalactic Astrophysics · Physics 2014-01-20 Yi-Fu Cai , Wen Zhao , Yang Zhang

We develop a method to reconstruct the primordial power spectrum, P(k), using both temperature and polarisation data from the joint analysis of a number of Cosmic Microwave Background (CMB) observations. The method is an extension of the…

Cosmology and Nongalactic Astrophysics · Physics 2009-07-22 Gavin Nicholson , Carlo R. Contaldi

We discuss cosmic microwave background anisotropies in models with an unconventional primordial power spectrum. In particular, we consider an initial power spectrum with some ``spiky'' corrections. Interestingly, such a primordial power…

Astrophysics · Physics 2010-04-05 Masahiro Kawasaki , Fuminobu Takahashi , Tomo Takahashi

We derive the primordial power spectrum of density fluctuations in the framework of quantum cosmology. For this purpose we perform a Born-Oppenheimer approximation to the Wheeler-DeWitt equation for an inflationary universe with a scalar…

General Relativity and Quantum Cosmology · Physics 2012-01-17 Claus Kiefer , Manuel Kraemer

Data from the Atacama Cosmology Telescope (ACT) and the South Pole Telescope (SPT), combined with the nine-year data release from the WMAP satellite, provide very precise measurements of the cosmic microwave background (CMB) angular…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 Micol Benetti , Martina Gerbino , William H. Kinney , Edward W. Kolb , Massimiliano Lattanzi , Alessandro Melchiorri , Luca Pagano , Antonio Riotto
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