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We show that deviations of the quantum state of the inflaton from the thermal vacuum of inflation may leave an imprint in the CMB anisotropies. The quantum dynamics of the inflaton in such a state produces corrections to the inflationary…

High Energy Physics - Theory · Physics 2009-11-10 Nemanja Kaloper , Manoj Kaplinghat

We confront the warm inflation observational predictions directly with the latest CMB data. We focus on a linear temperature (T) dissipative coefficient combined with the simplest model of inflation, a quartic chaotic potential. Although…

Cosmology and Nongalactic Astrophysics · Physics 2018-03-06 Mar Bastero-Gil , Sukannya Bhattacharya , Koushik Dutta , Mayukh Raj Gangopadhyay

Measurements of CMB temperature fluctuations by the Wilkinson Microwave Anisotropy Probe (WMAP) indicate that the fluctuation amplitude in one half of the sky differs from the amplitude in the other half. We show that such an asymmetry…

Astrophysics · Physics 2008-12-30 Adrienne L. Erickcek , Marc Kamionkowski , Sean M. Carroll

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

We investigate parity-violating signatures of temperature and polarization bispectra of the cosmic microwave background (CMB) in an inflationary model where a rolling pseudoscalar produces large equilateral tensor non-Gaussianity. By a…

Cosmology and Nongalactic Astrophysics · Physics 2013-11-22 Maresuke Shiraishi , Angelo Ricciardone , Shohei Saga

The observed power spectrum of the cosmic microwave background (CMB) is consistent with inflationary cosmology, which predicts a nearly scale-invariant power spectrum of quantum fluctuations of the inflaton field as they exit the Hubble…

High Energy Physics - Theory · Physics 2007-05-23 Leonard Parker

I discuss how parameters describing inflation in the very early universe may be related to primordial perturbation spectra. Precision observations of anisotropies in the cosmic microwave background (CMB) such as those provided by the WMAP…

Astrophysics · Physics 2015-06-24 David Wands

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

Slow-roll inflation generically makes several predictions: a flat Universe, primordial adiabatic density perturbations, and a stochastic gravity-wave background. Each inflation model will further predict specific relations between the…

Astrophysics · Physics 2007-05-23 Marc Kamionkowski

The BICEP/$\textit{Keck}$ (BK) series of cosmic microwave background (CMB) polarization experiments has, over the past decade and a half, produced a series of field-leading constraints on cosmic inflation via measurements of the "B-mode"…

We investigate the primordial gravitational waves (PGWs) in the general scenario where the inflation is preceded by a pre-inflationary stage with the effective equation of state $w$. Comparing with the results in the usual inflationary…

Cosmology and Nongalactic Astrophysics · Physics 2017-01-31 Kai Wang , Larissa Santos , Jun-Qing Xia , Wen Zhao

Inflation predicts a stochastic background of gravitational waves over a broad range of frequencies, from those accessible with cosmic microwave background (CMB) measurements, to those accessible directly with gravitational-wave detectors,…

Astrophysics · Physics 2008-11-26 Tristan L. Smith , Marc Kamionkowski , Asantha Cooray

Adams et al. (1997b) have noted that according to our current understanding of the unification of fundamental interactions, there should have been phase transitions associated with spontaneous symmetry breaking {\em during} the inflationary…

Astrophysics · Physics 2008-11-26 Jose Barriga , Enrique Gaztanaga , Mario Santos , Subir Sarkar

The prediction of a nearly scale-invariant spectrum of curvature and tensor fluctuations is among the main features of cosmic inflation. The current measurements of the primordial fluctuations in the cosmic microwave background (CMB)…

Cosmology and Nongalactic Astrophysics · Physics 2024-08-30 Marcos A. G. Garcia , Aline Pereyra-Flores

The inflationary cosmology paradigm is very successful in explaining the CMB anisotropy to the percent level. Besides the dependence on the inflationary model, the power spectra, spectral tilt and non-Gaussianity of the CMB temperature…

High Energy Physics - Theory · Physics 2014-02-18 Amjad Ashoorioon , Konstantinos Dimopoulos , M. M. Sheikh-Jabbari , Gary Shiu

We point out that the inclusion of a string component contributing around 5% to the CMB power spectrum amplitude on large scales can increase the preferred value of the spectral index n_s of density fluctuations measured by CMB experiments.…

Astrophysics · Physics 2009-11-11 Richard A. Battye , Bjorn Garbrecht , Adam Moss

The existence of the inflationary era in the early Universe seems to be strongly supported by recent CMB observations. However, only a few realistic inflation scenarios which have close relation to particle physics seem to have been known…

High Energy Physics - Phenomenology · Physics 2015-01-05 Romy H. S. Budhi , Shoichi Kashiwase , Daijiro Suematsu

I present recent work aimed at showing how currently competing theories of the early universe leave their imprint on the temperature anisotropies of the CMB radiation. We consider the 3-point correlation function, as well as the inherent…

Astrophysics · Physics 2007-05-23 Alejandro Gangui

Loop quantum cosmology allows to replace the original singularity by a quantum bounce followed by a phase of fast expansion called super-inflation. In this paper, we use a simple analytic description of super-inflation using the equation of…

General Relativity and Quantum Cosmology · Physics 2015-03-19 J. Ribassin , E. Huguet , K. Ganga

This work is focused on the study of early time cosmology and in particular on the study of inflation. After an introduction on the standard Big Bang theory, we discuss the physics of CMB and we explain how its observations can be used to…

General Relativity and Quantum Cosmology · Physics 2016-11-14 Mauro Pieroni