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In this article we review the theory of cosmological inflation with a particular focus on the beautiful connection it provides between the physics of the very small and observations of the very large. We explain how quantum mechanical…

Astrophysics · Physics 2010-04-30 Daniel Baumann , Hiranya V. Peiris

This thesis is dedicated to the study of inflationary scenarios based on string theory. Inflation is a brief period of accelerated expansion in the very early Universe which gives natural explanations for problems of the Standard Big Bang…

Cosmology and Nongalactic Astrophysics · Physics 2010-02-15 Larissa C. Lorenz

Motivated by the morphological measures in assessing the geometrical and topological properties of a generic cosmological stochastic field, we propose an extension of the weighted morphological measures, specifically the $n$th conditional…

Cosmology and Nongalactic Astrophysics · Physics 2025-08-19 Adeela Afzal , M. Alakhras , M. H. Jalali Kanafi , S. M. S. Movahed

Standard D-term inflation is studied in the framework of supergravity. D-term inflation produces cosmic strings, however it can still be compatible with CMB measurements without invoking any new physics. The cosmic strings contribution to…

High Energy Physics - Phenomenology · Physics 2009-11-10 Jonathan Rocher , Mairi Sakellariadou

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

During the last years it has become clear that global O(N) defects and U(1) cosmic strings do not lead to the pronounced first acoustic peak in the power spectrum of anisotropies of the cosmic microwave background which has recently been…

Astrophysics · Physics 2008-11-26 R. Durrer , M. Kunz , A. Melchiorri

We propose a new source for the cosmological density perturbation which is passive fluctuations of the inflaton driven dynamically by a colored quantum noise as a result of its coupling to other massive quantum fields. The created…

Astrophysics · Physics 2010-10-27 Chun-Hsien Wu , Kin-Wang Ng , Wolung Lee , Da-Shin Lee , Yeo-Yie Charng

Inflationary string cosmology backgrounds can amplify perturbations in a more efficient way than conventional inflationary backgrounds, because the perturbation amplitude may grow - instead of being constant - outside the horizon. If not…

High Energy Physics - Theory · Physics 2007-05-23 M. Gasperini

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

The curl-modes of Cosmic Microwave Background (CMB) polarization probe horizon-scale primordial gravitational waves related to inflation. A significant source of confusion is expected from a lensing conversion of polarization related to…

Astrophysics · Physics 2009-11-10 Asantha Cooray

We study the Cosmic Microwave Background (CMB) anisotropies produced by cosine-type quintessence models. In our analysis, effects of the adiabatic and isocurvature fluctuations are both taken into account. For purely adiabatic fluctuations…

Astrophysics · Physics 2009-11-06 Masahiro Kawasaki , Takeo Moroi , Tomo Takahashi

The latest Planck results show a power deficit in the temperature anisotropies near $\ell \approx 20$ in the cosmic microwave background (CMB). This observation can hardly be explained within the standard inflationary…

Cosmology and Nongalactic Astrophysics · Physics 2016-01-05 Yi-Fu Cai , Elisa G. M. Ferreira , Bin Hu , Jerome Quintin

String theory counterparts to Einstein's gravity, cosmology and inflation are described. A very tight upper bound on the Cosmic Gravitational Radiation Background (CGRB) of standard inflation is shown to be evaded in string cosmology, while…

High Energy Physics - Theory · Physics 2007-05-23 G. Veneziano

The advent of high resolution cosmic microwave background (CMB) experiments now allows studies on the temperature fluctuations at scales corresponding to few arcminutes and below. Though the reported excess power at $\ell \sim 2000 - 6000$…

Astrophysics · Physics 2009-11-07 Asantha Cooray , Alessandro Melchiorri

We give a brief review of the physics of acoustic oscillations in Cosmic Microwave Background (CMB) anisotropies. As an example of the impact of their detection in cosmology, we show how the present data on CMB angular power spectrum on…

Astrophysics · Physics 2015-06-24 C. Baccigalupi , A. Balbi , S. Matarrese , F. Perrotta , N. Vittorio

We propose an inflationary primordial feature model that can explain both the large and small-scale anomalies in the currently measured cosmic microwave background (CMB) anisotropy spectra, revealing a clip of adventurous history of the…

Cosmology and Nongalactic Astrophysics · Physics 2022-06-15 Matteo Braglia , Xingang Chen , Dhiraj Kumar Hazra

We continue our studies of the evolution and cosmological consequences of current-carrying cosmic string networks, described by a charge-velocity-dependent one scale (CVOS) model. We present a detailed calculation of the effects of these…

Cosmology and Nongalactic Astrophysics · Physics 2024-07-23 I. Yu. Rybak , C. J. A. P. Martins , Patrick Peter , E. P. S. Shellard

Cosmological perturbations generated quantum-mechanically (as a particular case, during inflation) possess statistical properties of squeezed quantum states. The power spectra of the perturbations are modulated and the angular distribution…

General Relativity and Quantum Cosmology · Physics 2009-10-22 L. P. Grishchuk

Fluctuations in the cosmic microwave background (CMB) contain information which has been pivotal in establishing the current cosmological model. These data can also be used to test well-motivated additions to this model, such as cosmic…

Cosmology and Nongalactic Astrophysics · Physics 2012-06-13 Stephen M. Feeney , Matthew C. Johnson , Daniel J. Mortlock , Hiranya V. Peiris

The curl (B) modes of cosmic microwave background (CMB) polarization anisotropies are a unique probe of the primordial background of inflationary gravitational waves (IGWs). Unfortunately, the B-mode polarization anisotropies generated by…

Astrophysics · Physics 2007-05-23 Kris Sigurdson , Asantha Cooray