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Related papers: An analytic approach to non-slow-roll inflation

200 papers

Robustness of the solutions to the inflaton potential inverse problem based on the slow-roll approximation is addressed. With that aim it is introduced a measure of the difference of the outputs obtained using first and second order…

Astrophysics · Physics 2009-11-13 H. P. de Oliveira , C. A. Terrero-Escalante

We use a numerical code for accurate computation of the amplitude of linear density perturbations and gravitational waves generated by single-field inflation models to study the accuracy of existing analytic results based on the slow-roll…

Astrophysics · Physics 2009-10-28 Ian J Grivell , Andrew R Liddle

Formulae are derived for the spectra of scalar curvature perturbations and gravitational waves produced during inflation, special cases of which include power law inflation, natural inflation in the small angle approximation and inflation…

General Relativity and Quantum Cosmology · Physics 2008-11-26 E. D. Stewart , D. H. Lyth

We consider the non-commutative inflation model of [3] in which it is the unconventional dispersion relation for regular radiation which drives the accelerated expansion of space. In this model, we study the evolution of linear cosmological…

High Energy Physics - Theory · Physics 2008-11-26 Seoktae Koh , Robert H. Brandenberger

Motivated by the prospect of testing inflation from precision cosmic microwave background observations, we present analytic results for scalar and tensor perturbations in single-field inflation models based on the application of uniform…

Astrophysics · Physics 2009-11-07 Salman Habib , Katrin Heitmann , Gerard Jungman , Carmen Molina-Paris

We extend the formalism of stochastic inflation to the setup of non-attractor inflation with a sound speed $c_s$. We obtain the Langevin equations for the superhorizon perturbations and calculate the stochastic corrections to curvature…

High Energy Physics - Theory · Physics 2020-12-09 Hassan Firouzjahi , Amin Nassiri-Rad , Mahdiyar Noorbala

Slow-roll inflation is studied in theories where the inflaton field is conformally coupled to the Ricci scalar. In particular, the case of Higgs field inflation in the context of the noncommutative spectral action is analyzed. It is shown…

High Energy Physics - Theory · Physics 2010-08-31 Michel Buck , Malcolm Fairbairn , Mairi Sakellariadou

We propose a general inverse formula for extracting inflationary parameters from the observed power spectrum of cosmological perturbations. Under the general slow-roll scheme, which helps to probe the properties of inflation in a model…

Astrophysics · Physics 2009-11-10 Minu Joy , Ewan D. Stewart , Jinn-Ouk Gong , Hyun-Chul Lee

The scalar perturbations in inflationary models, based on a two-component diagonal non-linear sigma model, are considered. For inhomogeneities generated at an inflationary stage, the law of motion of the comoving curvature ${\cal R}$ is…

Astrophysics · Physics 2007-05-23 N. A. Koshelev

Focusing on the local type primordial non-Gaussianities, we study the bispectrum and trispectrum during a non-minimal slow-roll inflation. We use the so-called $\delta N$ formalism to investigate the super-horizon evolution of the…

Cosmology and Nongalactic Astrophysics · Physics 2018-08-28 Kosar Asadi , Kourosh Nozari

We explore the noncommutative effect on single field inflation and compare with WMAP five-year data. First, we calculate the noncommutative effect from the potential and dynamical terms, and construct the general form of modified power…

Astrophysics · Physics 2009-06-18 Hong-Guang Zhang , Jie Ren , Xin-He Meng

The effective field theory (EFT) of inflation provides an essential picture to explore the effects of the unknown high energy physics in the single scalar field inflation models. For a generic EFT of inflation, possible high energy…

General Relativity and Quantum Cosmology · Physics 2019-12-03 Guang-Hua Ding , Jin Qiao , Qiang Wu , Tao Zhu , Anzhong Wang

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

The calculation of scalar gravitational and matter perturbations during multiple-field inflation valid to first order in slow roll is discussed. These fields may be the coordinates of a non-trivial field manifold and hence have non-minimal…

High Energy Physics - Phenomenology · Physics 2007-05-23 B. J. W. van Tent , S. Groot Nibbelink

We investigate the constant-roll inflation with non-minimally kinetic coupling to the Einstein tensor. With the slow-roll parameter $\eta_\phi = -\ddot{\phi}/(H\dot{\phi})$ being a constant, we calculate the power spectra for scalar and…

General Relativity and Quantum Cosmology · Physics 2024-07-22 Jie Liu , Yungui Gong , Zhu Yi

Stochastic inflation describes the global structure of the inflationary universe by modeling the super-Hubble dynamics as a system of matter fields coupled to gravity where the sub-Hubble field fluctuations induce a stochastic force into…

High Energy Physics - Theory · Physics 2008-11-26 Andrew J. Tolley , Mark Wyman

We extend our previous work on the enhancement of the curvature spectrum during inflation to the two-field case. We identify the slow-roll parameter $\eta$ as the quantity that can trigger the rapid growth of perturbations. Its two…

Cosmology and Nongalactic Astrophysics · Physics 2022-09-07 K. Boutivas , I. Dalianis , G. P. Kodaxis , N. Tetradis

Chain inflation is an alternative to slow-roll inflation in which the inflaton tunnels along a large number of consecutive minima in its potential. In this work we perform the first comprehensive calculation of the gravitational wave…

Cosmology and Nongalactic Astrophysics · Physics 2023-11-09 Katherine Freese , Aliki Litsa , Martin Wolfgang Winkler

This review article aims at presenting the theory of inflation. We first describe the background spacetime behavior during the slow-roll phase and analyze how inflation ends and the Universe reheats. Then, we present the theory of…

High Energy Physics - Theory · Physics 2009-11-10 Jerome Martin

An appealing feature of inflationary cosmology is the presence of a phase-space attractor, "slow roll", which washes out the dependence on initial field velocities. We investigate the robustness of this property under backreaction from…

General Relativity and Quantum Cosmology · Physics 2021-04-05 Julien Grain , Vincent Vennin