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Related papers: Final Thoughts on the Power Spectra of Scalar Pote…

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We review a recent formalism which derives the functional forms of the primordial -- tensor and scalar -- power spectra of scalar potential inflationary models. The formalism incorporates the case of geometries with non-constant first…

General Relativity and Quantum Cosmology · Physics 2019-06-13 D. J. Brooker , N. C. Tsamis , R. P. Woodard

We exploit a new numerical technique for evaluating the tree order contributions to the primordial scalar and tensor power spectra for scalar potential models of inflation. Among other things we use the formalism to develop a good analytic…

Cosmology and Nongalactic Astrophysics · Physics 2017-09-06 D. J. Brooker , N. C. Tsamis , R. P. Woodard

We study how the scalar power spectrum of single-scalar inflation depends functionally on models with features which have been proposed to explain anomalies in the data. We exploit a new formalism based on evolving the norm-squared of the…

General Relativity and Quantum Cosmology · Physics 2016-09-27 D. J. Brooker , N. C. Tsamis , R. P. Woodard

In conventional model independent approaches, the power spectrum of primordial perturbations is characterized by such free parameters as spectral index, its running, the running of running, and the tensor-to-scalar ratio. In this work we,…

Cosmology and Nongalactic Astrophysics · Physics 2017-03-15 Moslem Zarei

We suggest a new method to reconstruct, within canonical single-field inflation, the inflaton potential directly from the primordial power spectrum which may deviate significantly from near scale-invariance. Our approach relies on a more…

Cosmology and Nongalactic Astrophysics · Physics 2022-01-12 Ki-Young Choi , Jinn-Ouk Gong , Su-beom Kang , Rathul Nath Raveendran

We consider the superpotential formalism to describe the evolution of scalar fields during inflation, generalizing it to include the case with non-canonical kinetic terms. We provide a characterization of the attractor behaviour of the…

High Energy Physics - Theory · Physics 2016-02-24 Jaume Garriga , Yuko Urakawa , Filippo Vernizzi

We derive analytical expressions for the power spectra at the end of inflation in theories with two inflaton fields and non-canonical kinetic terms. We find that going beyond the slow-roll approximation is necessary and that the nature of…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-19 Carsten van de Bruck , Mathew Robinson

In this paper we break the scale invariance of the primordial power spectrum of curvature perturbations of inflation. Introducing a singular behaviour due to spontaneous symmetry breaking in the inflaton potential, we obtain fully analytic…

Astrophysics · Physics 2009-11-11 Jinn-Ouk Gong

A possible origin of the anomalous dip and bump in the primordial power spectrum, which are reconstructed from WMAP data corresponding to the multipole $\ell=100\sim 140$ by using the inversion method, is investigated as a consequence of…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 Kohei Kumazaki , Shuichiro Yokoyama , Naoshi Sugiyama

We extend the work of Contaldi et al. and derive analytical approximations for primordial power spectra arising from models of inflation which include primordial spatial curvature. These analytical templates are independent of any specific…

Cosmology and Nongalactic Astrophysics · Physics 2022-05-25 Ayngaran Thavanesan , Denis Werth , Will Handley

Purely geometrical arguments show that there exist classes of homospectral inflationary cosmologies, i.e. different expansion histories producing the same spectrum of comoving curvature perturbations. We develop a general algorithm to…

Cosmology and Nongalactic Astrophysics · Physics 2022-10-31 Alexander Gallego Cadavid , Antonio Enea Romano , Andrew R. Liddle

The tree order power spectra of primordial inflation depend upon the norm-squared of mode functions which oscillate for early times and then freeze in to constant values. We derive simple differential equations for the power spectra, that…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 Maria G. Romania , N. C. Tsamis , R. P. Woodard

We study the power spectra of f(R) inflation using a new technique in which the norm-squared of the mode functions is evolved. Our technique results in excellent analytic approximations for how the spectra depend upon the function $f(R)$.…

General Relativity and Quantum Cosmology · Physics 2016-09-08 D. J. Brooker , S. D. Odintsov , R. P. Woodard

We investigate the ability of current CMB data to reliably constrain the form of the primordial power spectrum generated during inflation. We attempt to identify more exotic power spectra that yield equally good fits to the data as simple…

Astrophysics · Physics 2009-06-23 Brian A. Powell , William H. Kinney

The spectrum of primordial fluctuations from inflation can be obtained using a mathematically controlled, and systematically extendable, uniform approximation. Closed-form expressions for power spectra and spectral indices may be found…

We study single-field inflationary models with steep step-like features in the potential that lead to the temporary violation of the slow-roll conditions during the evolution of the inflaton. These features enhance the power spectrum of the…

Cosmology and Nongalactic Astrophysics · Physics 2022-02-18 I. Dalianis , G. P. Kodaxis , I. D. Stamou , N. Tetradis , A. Tsigkas-Kouvelis

We consider the spectrum of primordial fluctuations produced by inflationary models where the inflaton potential is the sum of two exponential terms. A wide range of spectra result, with the only constraint being that the scalar spectrum…

Astrophysics · Physics 2009-09-25 Richard Easther

We prove an exact relation between the tensor and the scalar primordial power spectra generated during inflation. Such a mapping considerably simplifies the derivation of any power spectra as they can be obtained from the study of the…

Cosmology and Nongalactic Astrophysics · Physics 2013-09-04 Jose Beltran Jimenez , Marcello Musso , Christophe Ringeval

We construct non-linear inflaton potential energy densities that describe not-necessarily very-slowly-rolling closed and open inflation models, and compute tilted primordial spatial inhomogeneity power spectra that follow from quantum…

Cosmology and Nongalactic Astrophysics · Physics 2023-01-02 Bharat Ratra

In the ``natural inflation'' model, the inflaton potential is periodic. We show that Planck scale physics may induce corrections to the inflaton potential, which is also periodic with a greater frequency. Such high frequency corrections…

Astrophysics · Physics 2008-11-26 Xiulian Wang , Bo Feng , Mingzhe Li , Xue-Lei Chen , Xinmin Zhang
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