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Related papers: WMAP Bounds on Braneworld Tachyonic Inflation

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We present constraints on how far single field inflation may depart from the familiar slow-roll paradigm. Considering a fast-roll regime while requiring a (near)-scale-invariant power spectrum introduces large self-interactions for the…

Cosmology and Nongalactic Astrophysics · Physics 2012-09-12 Johannes Noller

We study observational viability of Natural Inflation with a tachyon field as inflaton. By obtaining the main perturbation parameters in this model, we perform a numerical analysis on the parameter space of the model and in confrontation…

Cosmology and Nongalactic Astrophysics · Physics 2018-05-23 Narges Rashidi , Kourosh Nozari , Oyvind Gron

The three-year data from WMAP are in stunning agreement with the simplest possible quadratic potential for chaotic inflation, as well as with new or symmetry-breaking inflation. We investigate the possibilities for incorporating these…

High Energy Physics - Theory · Physics 2009-11-11 J. Ellis , Z. Lalak , S. Pokorski , K. Turzynski

(Abridged) We present the angular power spectra derived from the 7-year maps and discuss the cosmological conclusions that can be inferred from WMAP data alone. The third acoustic peak in the TT spectrum is now well measured by WMAP. In the…

In this work we develop the patch formalism, an approach providing a very simple and compact description of braneworld-motivated cosmologies with nonstandard effective Friedmann equations. In particular, the Hubble parameter is assumed to…

High Energy Physics - Phenomenology · Physics 2007-05-23 Gianluca Calcagni

We present the angular power spectrum derived from the first-year Wilkinson Microwave Anisotropy Probe (WMAP) sky maps. We study a variety of power spectrum estimation methods and data combinations and demonstrate that the results are…

We study the inflationary dynamics of the universe in the Randall-Sandrum typeII Braneworld model. We consider both an inverse-power law and exponential potentials and apply the Slow-Roll approximation in high energy limit to derive…

General Relativity and Quantum Cosmology · Physics 2014-08-12 M. Bennai , H. Chakir , Z. Sakhi

We briefly discuss constraints on supersymmetric hybrid inflation models and examine the consistency of brane inflation models. We then address the implications for inflationary scenarios resulting from the strong constraints on the cosmic…

High Energy Physics - Theory · Physics 2014-10-28 Mairi Sakellariadou

Following an elegant approach that merge the effects of the stringy spacetime uncertainty relation into primordial perturbations suggested by Brandenberger and Ho, we show the mode equation up to the first order of non-commutative…

High Energy Physics - Theory · Physics 2009-11-10 Dao-jun Liu , Xin-zhou Li

Several anomalies appear to be present in the large-angle cosmic microwave background (CMB) anisotropy maps of WMAP, including the alignment of large-scale multipoles. Models in which isotropy is spontaneously broken (e.g., by a scalar…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-13 Haoxuan Zheng , Emory F. Bunn

We consider observational limits on a proposed model of the string landscape in inflation. In this scenario, effects from the decoherence of entangled quantum states in long-wavelength modes in the universe result in modifications to the…

Cosmology and Nongalactic Astrophysics · Physics 2016-11-08 William H. Kinney

We present a tachyonic field inflationary model in a teleparallel framework. We show that tachyonic coupled with the f(T) gravity model can describe the inflation era in which f(T) is an arbitrary function of torsion scalar T. For this…

General Relativity and Quantum Cosmology · Physics 2020-02-24 Amin Rezaei Akbarieh , Yousef Izadi

In their minimal form both supersymmetric and smooth hybrid inflation yield a scalar spectral index n_s close to 0.98, to be contrasted with the result n_s=0.951+0.015-0.019 from WMAP3. To realize better agreement, following hep-ph/0604198,…

High Energy Physics - Phenomenology · Physics 2008-11-26 Mansoor ur Rehman , V. N. Senoguz , Qaisar Shafi

Inflation elegantly provides initial conditions for the standard model of cosmology, while solving the horizon, flatness, and magnetic monopole problems. Inflationary models make predictions for the tensor-to-scalar ratio $r$ and the…

Cosmology and Nongalactic Astrophysics · Physics 2025-12-12 L. Balkenhol , E. Camphuis , F. Finelli , K. Benabed , F. R. Bouchet , J. Carron , S. Galli , E. Hivon , A. R. Khalife , L. Knox , C. L. Reichardt , A. Vitrier , W. L. K. Wu

We review the currrent cosmic parameter determinations of relevance to inflation using the WMAP-1year, Boomerang, CBI, Acbar and other CMB data. The basic steps in the pipelines which determine the bandpowers from the raw data from which…

Astrophysics · Physics 2009-11-10 J. R. Bond , C. R. Contaldi , A. M. Lewis , D. Pogosyan

We provide an explicit solution representing an anisotropic power law inflation within the framework of rolling tachyon model. This is generated by allowing a non-minimal coupling between the tachyon and the world-volume gauge field on…

High Energy Physics - Theory · Physics 2012-01-25 Samrat Bhowmick , Sudipta Mukherji

We present limits to the amplitude of non-Gaussian primordial fluctuations in the WMAP 1-year cosmic microwave background sky maps. A non-linear coupling parameter, f_NL, characterizes the amplitude of a quadratic term in the primordial…

Inflationary models with power-law potentials are starting to be severely constrained by the recent measurements of Cosmic Microwave Background anisotropies provided by the Planck Satellite and by the BICEP2 telescope. In particular, models…

Cosmology and Nongalactic Astrophysics · Physics 2019-05-03 Mehdi Shokri , Fabrizio Renzi , Alessandro Melchiorri

The most important criteria for a successful inflation are to explain the observed temperature anisotropy in the cosmic microwave background radiation, and exiting inflation in a vacuum where it can excite the Standard Model quarks and…

High Energy Physics - Theory · Physics 2011-05-31 Michele Cicoli , Anupam Mazumdar

We consider a class of inflationary models with small oscillations imprinted on an otherwise smooth inflaton potential. These oscillations are manifest as oscillations in the power spectrum of primordial perturbations, which then give rise…

Astrophysics · Physics 2009-11-13 Cédric Pahud , Marc Kamionkowski , Andrew R Liddle