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Related papers: Inflation after WMAP3

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We study the tilt of the primordial gravitational waves spectrum. A hint of blue tilt is shown from analyzing the BICEP2 and POLARBEAR data. Motivated by this, we explore the possibilities of blue tensor spectra from the very early universe…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-19 Yi Wang , Wei Xue

We derive an expression for the non-Gaussian cosmic-microwave-background (CMB) statistic $I_l^3$ defined recently by Ferreira, Magueijo, and G\'orski in terms of the slow-roll-inflation parameters $\epsilon$ and $\eta$. This result shows…

Astrophysics · Physics 2011-02-02 Limin Wang , Marc Kamionkowski

Power spectra always play an important role in the theory of inflation. In particular, the ability to reproduce the galaxy matter power spectrum and the CMB temperature angular power spectrum coefficients to high accuracy is often…

General Relativity and Quantum Cosmology · Physics 2019-11-01 Herbert W. Hamber , Lu Heng Sunny Yu

Using the latest observational data, we constrain the inflationary dynamics and the subsequent reheating epoch. Predictions for both phases can be significantly improved by employing numerically computed results compared to the slow-roll…

General Relativity and Quantum Cosmology · Physics 2026-01-29 Ying-Ying Ye , Bao-Min Gu

We have investigated inflation models that predict a very small value of the tensor-to-scalar ratio, $r$. The spectral index $n_s$, and the tensor-to-scalar ratio $r$, are strictly constrained by the Planck data. $n_s$ and $r$ are sensitive…

Cosmology and Nongalactic Astrophysics · Physics 2020-01-01 Koichi Hirano

The survey of models in astro-ph/0510441 is updated.For the first time, a large fraction of the models is ruled out at more than $3\sigma$.

Astrophysics · Physics 2009-11-11 Laila Alabidi , David H. Lyth

Scalar and tensorial cosmological perturbations generated in warm inflationary scenarios whose matter-radiation fluid is endowed with a viscous pressure are considered. Recent observational data from the WMAP experiment are employed to…

Astrophysics · Physics 2008-11-26 Sergio del Campo , Ramon Herrera , Diego Pavon

Observable quantities in cosmology are dimensionless, and therefore independent of the units in which they are measured. This is true of all physical quantities associated with the primordial perturbations that source cosmic microwave…

High Energy Physics - Theory · Physics 2015-05-20 Ignatios Antoniadis , Subodh P. Patil

There is solid theoretical and observational motivation behind the idea of scale-invariance as a fundamental symmetry of Nature. We consider a recently proposed classically scale-invariant inflationary model, quadratic in curvature and…

Cosmology and Nongalactic Astrophysics · Physics 2024-07-25 Chiara Cecchini , Mariaveronica De Angelis , William Giarè , Massimiliano Rinaldi , Sunny Vagnozzi

We propose a new scenario for early cosmology, where an inflationary de Sitter phase is obtained with a ghost condensate. The transition to radiation dominance is triggered by the ghost itself, without any slow-roll potential. Density…

High Energy Physics - Theory · Physics 2011-05-05 Nima Arkani-Hamed , Paolo Creminelli , Shinji Mukohyama , Matias Zaldarriaga

We demonstrate that the approximation for the number of inflationary e-folds commonly used in the literature can lead to highly inaccurate predictions for the amplitude of primordial gravitational waves. We show that such an approximation…

Cosmology and Nongalactic Astrophysics · Physics 2017-05-09 Siri Chongchitnan

We submit recent claims of a semi-significant detection of primordial tensor perturbations in the WMAP data to a closer scrutiny. Our conclusion is in brief that no such mode is present at a detectable level once the analysis is done more…

Cosmology and Nongalactic Astrophysics · Physics 2011-03-21 Eirik Gjerløw , Øystein Elgarøy

The effect of the length of inflation on the power spectra of scalar and tensor perturbations is estimated using the power-law inflation model with a scale factor of a(t) = t^q. Considering various pre-inflation models with…

Astrophysics · Physics 2007-05-23 Shiro Hirai , Tomoyuki Takami

The recently released data from the $\textit{Atacama Cosmology Telescope}$ (ACT) confirms that the primordial scalar spectrum is extremely flat. This, together with current upper bounds on the tensor-to-scalar ratio, implies that the…

High Energy Physics - Theory · Physics 2025-11-24 Arjun Berera , Suddhasattwa Brahma , Zizang Qiu , Rudnei O. Ramos , Gabriel S. Rodrigues

We are on the verge of the first precision testing of the inflationary cosmology as a model for the origin of structure in the Universe. I review the key predictions of inflation which can be used as observational tests, in the sense of…

Astrophysics · Physics 2007-05-23 Andrew R Liddle

Recent results from the Wilkinson Microwave Anisotropy Probe have been called a corroboration, or even a confirmation, of inflation. Yet, the results include features that require, at least, a significant distortion of what is usually meant…

Astrophysics · Physics 2007-05-23 Arthur Lue , Glenn D. Starkman , Tanmay Vachaspati

The model of Natural Inflation is examined in light of recent 3-year data from the Wilkinson Microwave Anisotropy Probe and shown to provide a good fit. The inflaton potential is naturally flat due to shift symmetries, and in the simplest…

High Energy Physics - Phenomenology · Physics 2008-11-26 Christopher Savage , Katherine Freese , William H. Kinney

The inflationary paradigm provides a robust description of the peculiar initial conditions which are required for the success of the Hot Big Bang model of cosmology, as well as of the recent precision measurements of temperature…

High Energy Physics - Theory · Physics 2008-11-26 C. P. Burgess

The Wilkinson Microwave Anisotropy Probe (WMAP) three year results are used to constraint non-minimal inflation models. Two different non-minimally coupled scalar field potentials are considered to calculate corresponding slow-roll…

Astrophysics · Physics 2008-12-25 Kourosh Nozari , S. Davood Sadatian

This review article aims at presenting the theory of inflation. We first describe the background spacetime behavior during the slow-roll phase and analyze how inflation ends and the Universe reheats. Then, we present the theory of…

High Energy Physics - Theory · Physics 2009-11-10 Jerome Martin
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