English
Related papers

Related papers: Cosmological parameter estimation and the spectral…

200 papers

The very basics of cosmological inflation are discussed. We derive the equations of motion for the inflaton field, introduce the slow-roll parameters, and present the computation of the inflationary perturbations and their connection to the…

General Relativity and Quantum Cosmology · Physics 2012-01-31 K. Enqvist

Why is non-Gaussianity interesting? One of generic predictions from inflationary scenarios is that primordial fluctuations are exactly Gaussian in linear order; however, the non-linearity in the inflation will produce weak non-Gaussianity.…

Astrophysics · Physics 2017-08-23 Eiichiro Komatsu , David N. Spergel

Primordial quantum fluctuations produced by inflation are conventionally assumed to be statistically homogeneous, a consequence of translational invariance. In this paper we quantify the potentially observable effects of a small violation…

Astrophysics · Physics 2010-04-14 Sean M. Carroll , Chien-Yao Tseng , Mark B. Wise

Some of the consequences for inflationary cosmology of a scale dependence (running) in the tilt of the scalar perturbation spectrum are considered. In the limit where the running is itself approximately scale-invariant, a relationship is…

Astrophysics · Physics 2015-06-24 James E. Lidsey , Reza Tavakol

The effect of including a Gauss-Bonnet contribution in the bulk action is investigated within the context of the steep inflationary scenario. When inflation is driven by an exponential inflaton field, this Gauss-Bonnet term allows the…

Astrophysics · Physics 2009-11-07 James E. Lidsey , N. J. Nunes

We investigate the impact of different choice of prior's range for the reheating epoch on cosmic inflation parameter inference in light of cosmic microwave background (CMB) anisotropy measurements from the {\em Planck} 2018 legacy release…

Cosmology and Nongalactic Astrophysics · Physics 2025-01-30 Mario Ballardini

We discuss the cosmological implications of the new constraints on the power spectrum of the Cosmic Microwave Background Anisotropy derived from a new high resolution analysis of the MAXIMA-1 measurement (Lee et al. 2001). The power…

The new three year WMAP data seem to confirm the presence of non-standard large scale features in the Cosmic Microwave Anisotropies power spectrum. While these features may hint at uncorrected experimental systematics, it is also possible…

Astrophysics · Physics 2009-11-11 Laura Covi , Jan Hamann , Alessandro Melchiorri , Anze Slosar , Irene Sorbera

In most current models of inflation based on a weakly self-coupled scalar matter field minimally coupled to gravity, the period of inflation lasts so long that, at the beginning of the inflationary period, the physical wavelengths of…

High Energy Physics - Theory · Physics 2008-11-26 Jerome Martin , Robert H. Brandenberger

We develop a model for correlations of cosmic microwave background anisotropy on the largest angular scales, based on standard causal geometrical relationships in slow-roll inflation. Unlike standard models based on quantized field modes,…

General Relativity and Quantum Cosmology · Physics 2023-08-02 Craig Hogan , Stephan S. Meyer , Nathaniel Selub , Frederick Wehlen

The standard inflationary model presents a simple scenario within which the homogeneity, isotropy and flatness of the universe appear as natural outcomes and, in addition, fluctuations in the energy density are originated during the…

Astrophysics · Physics 2023-03-08 E. Martinez-Gonzalez , P. Vielva

Current measurements of the temperature and polarization anisotropy power spectra of the Cosmic Microwave Background (CMB) seem to indicate that the naive expectation for the slow-roll hierarchy within the most simple inflationary paradigm…

Cosmology and Nongalactic Astrophysics · Physics 2020-12-10 Stefano Gariazzo , Olga Mena , Victor Miralles , Héctor Ramírez , Lotfi Boubekeur

Cosmic microwave background (CMB) temperature anisotropies have and will continue to revolutionize our understanding of cosmology. The recent discovery of the previously predicted acoustic peaks in the power spectrum has established a…

Astrophysics · Physics 2011-07-19 Wayne Hu , Scott Dodelson

Following a new quantum cosmological model proposed by Dvali and Gomez, we quantitatively investigate possible modifications to the Hubble parameter and following corrections to the cosmic microwave background spectrum. In this model,…

General Relativity and Quantum Cosmology · Physics 2015-09-16 Roberto Casadio , Florian Kuhnel , Alessio Orlandi

Determining the energy scale of inflation is crucial to understand the nature of inflation in the early Universe. We place observational constraints on the energy scale of the observable part of the inflaton potential by combining the…

Cosmology and Nongalactic Astrophysics · Physics 2011-05-12 Zong-Kuan Guo , Dominik J. Schwarz , Yuan-Zhong Zhang

In this work we explore the possibility of variations in the primordial scalar power spectrum around the power-law shape, as predicted by single-field slow-roll inflationary scenarios. We search for the trace of these fluctuations in a…

Cosmology and Nongalactic Astrophysics · Physics 2022-02-09 Marzieh Farhang , Muhammad Sadegh Esmaeilian

We consider a novel model of cosmic inflation. In our model one does not need any specific matter field to drive inflation, but inflation stems from the microscopic, Planck scale structure of spacetime, thus being of quantum gravitational…

General Relativity and Quantum Cosmology · Physics 2014-08-28 Jarmo Mäkelä

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

Precision measurement of the scalar perturbation spectral index, n_s, from the Wilkinson Microwave Anisotropy Probe temperature angular power spectrum requires the subtraction of unresolved point source power. Here we reconsider this issue.…

Astrophysics · Physics 2009-11-13 K. M. Huffenberger , H. K. Eriksen , F. K. Hansen , A. J. Banday , K. M. Gorski

Inflation is now an accepted paradigm in standard cosmology, with its predictions consistent with observations of the cosmic microwave background. It lacks, however, a firm physical theory, with many possible theoretical origins beyond the…

Astrophysics · Physics 2009-01-16 Nishant Agarwal , Rachel Bean