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Related papers: Natural Inflation: status after WMAP 3-year data

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We provide a detailed study of natural inflation with a periodic non-minimal coupling, which is a well-motivated inflationary model that admits an explicit UV completion. We demonstrate that this construction can satisfy the most recent…

Cosmology and Nongalactic Astrophysics · Physics 2024-03-18 Alberto Salvio , Simone Sciusco

We construct a hybrid-inflation model where the inflaton potential is generated radiatively, as gauge symmetries guarantee it to be accidentally flat at tree level. The model can be regarded as a small-field version of Natural Inflation,…

Cosmology and Nongalactic Astrophysics · Physics 2024-11-18 Felix Brümmer , Giacomo Ferrante , Michele Frigerio

For the models of inflation driven by the potential energy of an inflaton field $\phi$, the covariant Galileon Lagrangian $(\partial\phi)^2\Box \phi$ generally works to slow down the evolution of the field. On the other hand, if the…

General Relativity and Quantum Cosmology · Physics 2013-01-29 Junko Ohashi , Shinji Tsujikawa

If the inflaton is a pseudo-scalar axion, the axion shift symmetry can protect the flatness of its potential from too large radiative corrections. This possibility, known as natural inflation, requires an axion scale which is greater than…

High Energy Physics - Phenomenology · Physics 2009-11-10 Jihn E. Kim , Hans Peter Nilles , Marco Peloso

We present the final nine-year maps and basic results from the WMAP mission. We provide new nine-year full sky temperature maps that were processed to reduce the asymmetry of the effective beams. Temperature and polarization sky maps are…

In this addendum to Phys.Rev. D74 (2006) 023502, we present an update of cosmological constraints on single-field inflation in light of the Wilkinson Microwave Ansiotropy Probe satellite mission five-year results (WMAP5). We find that the…

Astrophysics · Physics 2008-11-26 William H. Kinney , Edward W. Kolb , Alessandro Melchiorri , Antonio Riotto

In this paper we study a novel realization of inflation, based on Weyl invariant gravity with torsion. We show that requiring the classical action for the scalar field to be Weyl invariant introduces a dilaton which induces a non trivial…

General Relativity and Quantum Cosmology · Physics 2019-01-16 A. Barnaveli , S. Lucat , T. Prokopec

We not only reconstruct the slow-roll parameters for fit to the running spectral index from WMAP three-year data in the usual slow-roll inflation model and noncommutative inflation model, but also investigate the evolution of these…

Astrophysics · Physics 2008-11-26 Qing-Guo Huang

A simple cosmological model with only six parameters (matter density, Omega_m h^2, baryon density, Omega_b h^2, Hubble Constant, H_0, amplitude of fluctuations, sigma_8, optical depth, tau, and a slope for the scalar perturbation spectrum,…

In warm inflation models there is the requirement of generating large dissipative couplings of the inflaton with radiation, while at the same time, not de-stabilising the flatness of the inflaton potential due to radiative corrections. One…

High Energy Physics - Phenomenology · Physics 2015-05-28 Hiranmaya Mishra , Subhendra Mohanty , Akhilesh Nautiyal

We derive new constraints on the Hubble function H(phi) and subsequently on the inflationary potential V(phi) from WMAP 3-year data combined with the Sloan Luminous Red Galaxy survey (SDSS-LRG), using a new methodology which appears to be…

Astrophysics · Physics 2009-06-23 Julien Lesgourgues , Alexei A. Starobinsky , Wessel Valkenburg

We study the single field slow-roll inflation models that better fit the available CMB and LSS data including the three years WMAP data: new inflation and hybrid inflation. We study them as effective field theories in the Ginsburg-Landau…

Astrophysics · Physics 2009-11-11 H. J. de Vega , N. G. Sanchez

Supersymmetry-based hybrid inflation models (referred to as `spontaneously broken supersymmetry' by the Planck collaboration) are attractive for several reasons, including the appealing feature that inflation is associated with local gauge…

Cosmology and Nongalactic Astrophysics · Physics 2025-04-22 Mansoor Ur Rehman , Qaisar Shafi

We consider natural inflation in a warm inflation framework with a temperature-dependent dissipative coefficient $\Gamma \propto T^3$. Natural inflation can be compatible with the Planck 2018 results with such warm assistance. With no a…

Cosmology and Nongalactic Astrophysics · Physics 2021-05-05 Yakefu Reyimuaji , Xinyi Zhang

We analyze a model of hybrid natural inflation based on the smallest non-Abelian discrete group S_3. Leading invariant terms in the scalar potential have an accidental global symmetry that is spontaneously broken, providing a…

High Energy Physics - Phenomenology · Physics 2015-06-22 Christopher D. Carone , Joshua Erlich , Marc Sher , Raymundo Ramos

We study the linear perturbation of the recently proposed model of inflation where a uniform gauge-kinetic coupling of the inflaton to multiple vector fields breaks the cosmic no-hair conjecture while maintaining the isotropy. We derive the…

Cosmology and Nongalactic Astrophysics · Physics 2012-10-09 Kei Yamamoto

This paper studies the stability of warm inflationary solutions when the viscous pressure is taken into account. The latter is a very natural and physically motivated ingredient of warm inflation and is seen to widen the stability range of…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-19 Sergio del Campo , Ramón Herrera , Diego Pavón , José R. Villanueva

Usual inflation is realized with a slow rolling scalar field minimally coupled to gravity. In contrast, we consider dynamics of a scalar with a flat effective potential, conformally coupled to gravity. Surprisingly, it contains an attractor…

High Energy Physics - Theory · Physics 2008-11-26 Lev Kofman , Shinji Mukohyama

In Natural Inflation, the Inflaton is a pseudo-Nambu-Goldstone boson which acquires a mass by explicit breaking of a global shift symmetry at scale f. In this case, for small field values, the potential is flat and stable under radiative…

High Energy Physics - Phenomenology · Physics 2011-05-09 Cristiano Germani , Alex Kehagias

Observations of anisotropies in the cosmic microwave background by the Wilkinson Microwave Anisotropy Probe suggest the possibility of oscillations in the primordial density perturbation. Such deviations from the usually assumed scale-free…

Astrophysics · Physics 2011-02-16 Paul Hunt , Subir Sarkar
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