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Related papers: Issues Concerning Loop Corrections to the Primordi…

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A relaxed primordial power spectrum (PPS) of scalar perturbations arising from inflation can impact the dark radiation constraints obtained from Cosmic Microwave Background and other cosmological measurements. If inflation produces a…

Cosmology and Nongalactic Astrophysics · Physics 2017-01-25 Stefano Gariazzo

In this paper we study slow-roll inflation with holonomy corrections from loop quantum cosmology. Both tensor and scalar power spectra of primordial perturbations are computed up to the first order in slow-roll parameters and $V/\rho_{c}$,…

General Relativity and Quantum Cosmology · Physics 2015-06-17 Jakub Mielczarek

In the present paper we discuss how trans-Planckian physics affects inflationary vacuum fluctuations and primordial density perturbations. The trans-Planckian problem during inflation has been widely discussed in literature, but it is still…

High Energy Physics - Theory · Physics 2019-08-21 Hiroki Matsui

We analyze the effects of the holographic dark energy model in a single field slow-roll inflation, taking into account both the holographic and the dark radiation components. In particular, we obtain the background evolution and compute the…

Cosmology and Nongalactic Astrophysics · Physics 2022-09-07 Paola C. M. Delgado , Alexander Ganz , Chunshan Lin

We quantify the slow-roll corrections to primordial density perturbations arising from inflation driven by a four-dimensional scalar field with a monomial potential in a five-dimensional non-compact bulk spacetime. Although the difference…

Astrophysics · Physics 2008-11-26 Kazuya Koyama , Andrew Mennim , David Wands

The possibility that quantum geometry effects may alleviate the apparent tensions existing at large angular scales in the observations of the Cosmic Microwave Background explains the increasing interest in considering primordial…

General Relativity and Quantum Cosmology · Physics 2024-07-26 Guillermo A. Mena Marugán , Antonio Vicente-Becerril , Jesús Yébana Carrilero

The linear and quadratic perturbations for a scalar-tensor model with non-minimal coupling to curvature, coupling to the Gauss-Bonnet invariant and non-minimal kinetic coupling to the Einstein tensor are developed. The quadratic action for…

General Relativity and Quantum Cosmology · Physics 2019-09-24 L. N. Granda , D. F. Jimenez

We consider inflation with a constant rate of rolling in which a complex scalar field plays the role of inflaton during the inflationary epoch. We implement the inflationary analysis for an accredited angular speed $\dot{\theta}$ which…

General Relativity and Quantum Cosmology · Physics 2024-05-16 Ramón Herrera , Mehdi Shokri , Jafar Sadeghi

The next generation of cosmological observations will be sensitive to small deviations from a pure power law in the primordial power spectrum of the curvature perturbations. In the context of slow-roll inflation, these deviations are…

Cosmology and Nongalactic Astrophysics · Physics 2022-09-15 Pierre Auclair , Christophe Ringeval

Primordial inflation results in the production of a vast ensemble of highly infrared, massless, minimally coupled scalars. We use a recent fully renormalized computation of the one loop contribution to the graviton self-energy from these…

General Relativity and Quantum Cosmology · Physics 2012-01-04 Sohyun Park , R. P. Woodard

We consider Cosmic Microwave Background constraints on inflation models for which the primordial power spectrum is a mixture of perturbations generated by inflaton fluctuations and fluctuations in a curvaton field. If future experiments do…

Cosmology and Nongalactic Astrophysics · Physics 2013-09-10 William H. Kinney , Azadeh Moradinezhad Dizgah , Antonio Riotto

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

The decrease of both the rolling speed of the inflaton and the sound speed of the curvature perturbations can amplify the curvature perturbations during inflation so as to generate a sizable amount of primordial black holes. In the…

General Relativity and Quantum Cosmology · Physics 2024-01-17 Rongrong Zhai , Hongwei Yu , Puxun Wu

In this paper, we suppose that the universe begins in a holographic thermal equilibrium phase with the diverged correlation length, and the phase transition to the radiation phase of standard cosmology goes with the abrupt reducing of…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Yun-Song Piao

We discuss a new mechanism to enhance the spectrum of primordial tensor fluctuations in single field inflationary scenarios. The enhancement relies on a transitory non-attractor inflationary phase, which amplifies the would-be decaying…

General Relativity and Quantum Cosmology · Physics 2019-02-22 Maria Mylova , Ogan Özsoy , Susha Parameswaran , Gianmassimo Tasinato , Ivonne Zavala

We compute the primordial scalar, vector and tensor metric perturbations arising from quantum field inflation. Quantum field inflation takes into account the nonperturbative quantum dynamics of the inflaton consistently coupled to the…

Astrophysics · Physics 2009-11-10 F. J. Cao , H. J. de Vega , N. G. Sanchez

The computation of the spectrum of primordial perturbations, generated by a scalar field during the super-inflationary phase of Loop Quantum Cosmology, is revisited. The calculation is performed for two different cases. The first considers…

Astrophysics · Physics 2009-11-11 D. J. Mulryne , N. J. Nunes

Inflationary models predict a correlation between primordial density perturbations (scalar metric perturbations) and gravitational waves (tensor metric perturbations) in the form of a scalar-scalar-tensor three-point correlation, or…

Cosmology and Nongalactic Astrophysics · Physics 2013-08-09 Liang Dai , Donghui Jeong , Marc Kamionkowski

The Wilkinson Microwave Anisotropy Probe microwave background data suggest that the primordial spectrum of scalar curvature fluctuations is suppressed at small wavenumbers. We propose a UV/IR mixing effect in small-field inflationary models…

High Energy Physics - Phenomenology · Physics 2009-11-10 A. Buchel , F. A. Chishtie , V. Elias , Katherine Freese , R. B. Mann , D. G. C. McKeon , T. G. Steele

With an energy scale that can be as high as $10^{14}\,{\rm GeV}$, inflation may provide a unique probe of high-energy physics. Both scalar and tensor fluctuations generated during this early accelerated expansion contain crucial information…

Cosmology and Nongalactic Astrophysics · Physics 2020-08-25 Laura Iacconi , Matteo Fasiello , Hooshyar Assadullahi , Emanuela Dimastrogiovanni , David Wands