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Related papers: Modification from Noncommutative Inflation

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We compute the amplitude of the non-Gaussianities in inflationary models with multiple, uncoupled scalar fields. This calculation thus applies to all models of assisted inflation, including N-flation, where inflation is driven by multiple…

Astrophysics · Physics 2010-10-27 Thorsten Battefeld , Richard Easther

The observational constraints on the primordial power spectrum have tightened considerably with the release of the first year analysis of the WMAP observations, especially when combined with the results from other CMB experiments and galaxy…

High Energy Physics - Phenomenology · Physics 2009-11-10 Dominik J. Schwarz , Cesar A. Terrero-Escalante

Modular invariance is a striking symmetry in string theory, which may keep stringy corrections under control. In this paper, we investigate a phenomenological consequence of the modular invariance, assuming that this symmetry is preserved…

High Energy Physics - Theory · Physics 2016-08-17 Tatsuo Kobayashi , Daisuke Nitta , Yuko Urakawa

We discuss an inflation model, in which the inflation is driven by a single scalar field with exponential potential on a warped DGP brane. In contrast to the power law inflation in standard model, we find that the inflationary phase can…

High Energy Physics - Theory · Physics 2009-11-10 Rong-Gen Cai , Hongsheng Zhang

We derive the general Ward identities for scale and special conformal transformations in theories of single field inflation. Our analysis is model independent and based on symmetry considerations alone. The identities we obtain are valid to…

High Energy Physics - Theory · Physics 2016-01-19 Nilay Kundu , Ashish Shukla , Sandip P. Trivedi

An inflationary model in the framework of noncommutative space-time may generate a nontrivial running of the scalar spectral index, but usually induces a large tensor-to-scalar ratio simultaneously. With the latest observational data from…

Cosmology and Nongalactic Astrophysics · Physics 2013-07-11 Nan Li , Xin Zhang

We assay how inflationary models whose properties are dominated by the dynamics of a single scalar field are constrained by cosmic microwave background (CMB) data from the Wilkinson Microwave Anisotropy Probe (WMAP). We classify…

High Energy Physics - Phenomenology · Physics 2009-09-15 V. Barger , Hye-Sung Lee , Danny Marfatia

A thorough MCMC analysis of any inflationary model against the current cosmological data is essential for assessing the validity of such a model as a viable inflationary model. Warm Inflation, producing both thermal and quantum…

Cosmology and Nongalactic Astrophysics · Physics 2024-10-29 Umang Kumar , Suratna Das

We study the effects of the non-attractor initial conditions for the canonical single-field inflation. The non-attractor stage can last only several $e$-folding numbers, and should be followed by hilltop inflation. This two-stage evolution…

Cosmology and Nongalactic Astrophysics · Physics 2016-10-13 Yi-Fu Cai , Jinn-Ouk Gong , Dong-Gang Wang , Ziwei Wang

We consider constraints on inflation driven by a single, minimally coupled scalar field in the light of the WMAP5 dataset, as well as ACBAR and the SuperNova Legacy Survey. We use the Slow Roll Reconstruction algorithm to derive optimal…

Astrophysics · Physics 2014-11-18 Hiranya V. Peiris , Richard Easther

We determine the power spectrum for inflation models covering all regimes from cold (isentropic) to warm (nonisentropic) inflation. We work in the context of the stochastic inflation approach, which can nicely describe both types of…

Cosmology and Nongalactic Astrophysics · Physics 2013-03-27 Rudnei O. Ramos , L. A. da Silva

The latest results from PLANCK impose strong constraints on features in the spectrum of the curvature perturbations from inflation. We analyse the possibility of particle production induced by sharp turns of the trajectory in field space in…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-18 Maciej Konieczka , Raquel H. Ribeiro , Krzysztof Turzynski

Inflation in cosmology is a specific stage preceding the Big Bang, aimed at solving both old background problems and new perturbation issues. Single-field inflation is a candidate to illustrate the picture of the initial universe, and…

Cosmology and Nongalactic Astrophysics · Physics 2025-05-21 Guanqiao Liu

We extract parameters relevant for distinguishing among single-field inflation models from the Wilkinson Microwave Anisotropy Probe (WMAP) three-year data set, and also from WMAP in combination with the Sloan Digital Sky Survey (SDSS)…

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

Picking out DBI scalar field as inflation, the slow-rolling inflationary scenario is studied by attributing an exponential time function to scale factor; known as intermediate inflation. The perturbation parameters of the model are…

General Relativity and Quantum Cosmology · Physics 2017-08-15 N. Nazavari , A. Mohammadi , Z. Ossoulian , Kh. Saaidi

In a general single field inflationary model we consider the effects of long wavelength scalar fluctuations on the effective expansion rate and equation of state seen by a class of free falling observers, using a physical gauge invariant…

General Relativity and Quantum Cosmology · Physics 2013-08-06 Giovanni Marozzi , Gian Paolo Vacca

We analyze the trajectories for multifield DBI inflation, which can arise in brane inflation models, and show that the trajectories are the same as in typical slow roll inflation. We calculate the power spectrum and find that the higher…

High Energy Physics - Theory · Physics 2008-11-26 Min-xin Huang , Gary Shiu , Bret Underwood

We show that the generalized slow-roll approach for calculating the power spectrum where the inflationary slow roll parameters are neither small nor slowly varying can be readily extended to models with non-canonical kinetic terms in the…

Cosmology and Nongalactic Astrophysics · Physics 2011-08-09 Wayne Hu

We study the out of equilibrium dynamics of inflationary phase transitions and compute the resulting spectrum of metric perturbations relevant to observation. We show that simple single field models of inflation may produce an adiabatic…

Astrophysics · Physics 2016-11-03 D. Cormier , R. Holman

The first year WMAP measurement of the CMB temperature anisotropy is intriguingly consistent with a larger running of the inflationary scalar spectral index than would be expected for single-field inflation. We revisit the issue of a large…

Astrophysics · Physics 2009-11-11 James M. Cline , Loison Hoi
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