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We revisit the inflationary dynamics in detail for theories with Gauss-Bonnet gravity coupled to scalar functions, in light of the Planck data. Considering the chaotic inflationary scenario, we constrain the parameters of two models…

General Relativity and Quantum Cosmology · Physics 2017-02-08 Srijit Bhattacharjee , Debaprasad Maity , Rupak Mukherjee

Single-field models of $\alpha$-attractor quintessential inflation provide a unified picture of the two periods of early- and late-time cosmic acceleration, where both inflation and dark energy are described by a single scalar degree of…

Cosmology and Nongalactic Astrophysics · Physics 2021-04-05 Yashar Akrami , Santiago Casas , Senwen Deng , Valeri Vardanyan

We study scale dependence of the cosmic microwave background (CMB) power spectrum in a class of small, single-field models of inflation which lead to a high value of the tensor to scalar ratio. The inflaton potentials that we consider are…

Cosmology and Nongalactic Astrophysics · Physics 2018-05-28 Ira Wolfson , Ram Brustein

Recent Planck measurements show some CMB anomalies on large angular scales, which confirms the early observations by WMAP. We show that an inflationary model, in which before the slow-roll inflation the Universe is in a superinflationary…

Cosmology and Nongalactic Astrophysics · Physics 2014-08-11 Zhi-Guo Liu , Zong-Kuan Guo , Yun-Song Piao

[Abridged] A variety of model-dependent as well as model-independent approaches suggest that certain localized features in the primordial scalar power spectrum can lead to a significantly better fit to the observed anisotropies in the…

Cosmology and Nongalactic Astrophysics · Physics 2026-04-16 Alipriyo Hoory , Dhiraj Kumar Hazra , L. Sriramkumar

I review the general aspects of cosmological parameter estimation from observations of the cosmic microwave background (CMB) temperature anisotropies in the framework of inflationary adiabatic models. The most recent CMB datasets are…

Astrophysics · Physics 2009-10-31 A. Balbi

We present an implementation of an optimal CMB trispectrum estimator which accounts for anisotropic noise and incomplete sky coverage. We use a general separable mode expansion which can and has been applied to constrain both primordial and…

Cosmology and Nongalactic Astrophysics · Physics 2010-12-30 J. R. Fergusson , D. M. Regan , E. P. S. Shellard

We update the search for features in the Cosmic Microwave Background (CMB) power spectrum due to transient reductions in the speed of sound, using Planck 2015 CMB temperature and polarisation data. We enlarge the parameter space to much…

Cosmology and Nongalactic Astrophysics · Physics 2017-10-25 Jesus Torrado , Bin Hu , Ana Achucarro

We assess the potential of a future large-volume photometric redshift survey to constrain observational inflationary parameters using three large-scale structure observables: the angular shear and galaxy power spectra, and the cluster mass…

Cosmology and Nongalactic Astrophysics · Physics 2014-09-12 Tobias Basse , Jan Hamann , Steen Hannestad , Yvonne Y. Y. Wong

We study reconstruction of the lensing potential power spectrum from CMB temperature data, with an eye to the Planck experiment. We work with the optimal quadratic estimator of Okamoto and Hu, which we characterize thoroughly in application…

Cosmology and Nongalactic Astrophysics · Physics 2011-02-23 Duncan Hanson , Anthony Challinor , George Efstathiou , Pawel Bielewicz

The fine-structure constant, $\alpha$, controls the strength of the electromagnetic interaction. There are extensions of the standard model in which $\alpha$ is dynamical on cosmological length and time-scales. The physics of the cosmic…

Cosmology and Nongalactic Astrophysics · Physics 2019-02-27 Tristan L. Smith , Daniel Grin , David Robinson , Davy Qi

The newly released Planck CMB data place tight constraints on slow-roll inflationary models. Some of commonly discussed inflationary potentials are disfavored due mainly to the large tensor-to-scalar ratio. In this paper we show that these…

High Energy Physics - Theory · Physics 2013-12-05 Peng-Xu Jiang , Jian-Wei Hu , Zong-Kuan Guo

We revisit the constraints on inflation models by using the current cosmological observations involving the latest local measurement of the Hubble constant ($H_{0} = 73.00\pm 1.75$ km s $^{-1}$ Mpc$^{-1}$). We constrain the primordial power…

Cosmology and Nongalactic Astrophysics · Physics 2017-12-20 Rui-Yun Guo , Xin Zhang

Probing correlations among short and long-wavelength cosmological fluctuations is known to be decisive for deepening the current understanding of inflation at the microphysical level. Spectral distortions of the CMB can be caused by…

Cosmology and Nongalactic Astrophysics · Physics 2016-12-14 Emanuela Dimastrogiovanni , Razieh Emami

We present posterior sample-based cosmic microwave background (CMB) constraints from Planck LFI and WMAP observations derived through global end-to-end Bayesian processing. We use these samples to study correlations between CMB, foreground,…

We eliminate the parameters originally present in models of inflation of the $\alpha$-attractor type in favor of the scalar spectral index $n_s$ and the tensor-to-scalar ratio $r$. We then write expressions for the number of $e$-folds…

Cosmology and Nongalactic Astrophysics · Physics 2022-06-02 Gabriel German

Over the last few years, a large family of cosmological attractor models has been discovered, which can successfully match the latest inflation-related observational data. Many of these models can also describe a small cosmological constant…

High Energy Physics - Theory · Physics 2018-07-02 Yashar Akrami , Renata Kallosh , Andrei Linde , Valeri Vardanyan

Reheating in inflationary cosmology is essential for understanding the early universe, influencing particle production, thermalization, and the primordial power spectrum. Crucial quantities defined during the reheating epoc, such as the…

Cosmology and Nongalactic Astrophysics · Physics 2025-01-16 Gabriel German

This paper aims to perform a phenomenological parametrisation of the standard cosmological model, $\Lambda$CDM, to weigh the different physical processes that define the pattern of the angular power spectra of the Cosmic Microwave…

Cosmology and Nongalactic Astrophysics · Physics 2022-11-22 M. Ruiz-Granda , P. Vielva

We present a detailed analysis of present and future Cosmic Microwave Background constraints of the value of the fine-structure constant, $\alpha$. We carry out a more detailed analysis of the WMAP first-year data, deriving state-of-the-art…

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