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Related papers: New perspectives on constant-roll inflation

200 papers

It is shown that a large class of higher-order (i.e. non-quadratic) scalar kinetic terms can, without the help of potential terms, drive an inflationary evolution starting from rather generic initial conditions. In many models, this…

High Energy Physics - Theory · Physics 2008-11-26 C. Armendariz-Picon , T. Damour , V. Mukhanov

We investigate in detail the implications of the constant-roll condition on the inflationary era of a scalar field coupled to a teleparallel $f(T)$ gravity. The resulting cosmological equations constitute a reconstruction technique which…

General Relativity and Quantum Cosmology · Physics 2018-07-17 A. Awad , W. El Hanafy , G. G. L. Nashed , S. D. Odintsov , V. K. Oikonomou

We describe models of single-field inflation with small and sharp step features in the potential (and sound speed) of the inflaton field, in the context of the Effective Field Theory of Inflation. This approach allows us to study the…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-16 Nicola Bartolo , Dario Cannone , Sabino Matarrese

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

The curvature perturbation in a model of constant-roll (CR) inflation is interpreted in view of the logarithmic duality discovered in Ref. [1] according to the $\delta N$ formalism. We confirm that the critical value…

Cosmology and Nongalactic Astrophysics · Physics 2025-02-21 Ryoto Inui , Hayato Motohashi , Shi Pi , Yuichiro Tada , Shuichiro Yokoyama

We calculate the power spectrum of curvature perturbations when the inflaton field is rolling over the top of a local maximum of a potential. We show that the evolution of the field can be decomposed into a late-time attractor, which is…

Astrophysics · Physics 2008-11-26 Konstantinos Tzirakis , William H. Kinney

There is a duality in the observables $n_s$, $r$ and the inflaton potential between large and small $\eta_H$ for the constant-roll inflation if the slow-roll parameter $\epsilon_H$ is negligible. In general, the duality between $\eta_H$ and…

General Relativity and Quantum Cosmology · Physics 2024-04-30 Yue Wang , Qing Gao , Shengqing Gao , Yungui Gong

In this paper we investigate the inflationary phenomenology of an Einstein-Gauss-Bonnet theory compatible with the GW170817 event, by imposing the constant-roll evolution on the scalar field. We develop the constant-roll GW170817-compatible…

General Relativity and Quantum Cosmology · Physics 2020-09-15 S. D. Odintsov , V. K. Oikonomou , F. P. Fronimos , S. A. Venikoudis

Hyperbolic inflation is an extension of the slow-roll inflation in multi-field models. We extend hyperbolic inflation by adding a gauge field and find four-type attractor solutions: slow-roll inflation, hyperbolic inflation, anisotropic…

High Energy Physics - Theory · Physics 2023-06-27 Chong-Bin Chen , Jiro Soda

We study the ultra slow roll model in the context of stochastic inflation. Using stochastic $\delta N$ formalism, we calculate the mean number of $e$-folds, the power spectrum, the bispectrum and the stochastic corrections into these…

High Energy Physics - Theory · Physics 2019-01-23 Hassan Firouzjahi , Amin Nassiri-Rad , Mahdiyar Noorbala

We calculate the scalar gravitational and matter perturbations in the context of slow-roll inflation with multiple scalar fields, that take values on a (curved) manifold, to first order in slow roll. For that purpose a basis for these…

High Energy Physics - Phenomenology · Physics 2011-10-11 S. Groot Nibbelink , B. J. W. van Tent

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

The slow-roll approximation is the usual starting point to study the constraints imposed on the inflaton potential parameters by the observational data. We show that, for a potential exhibiting at least two extrema and giving rise to a…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Tiago Charters , Jose P. Mimoso , Ana Nunes

We extend a previous analysis concerning cosmological fluids with generalized equations of state in order to study inflationary scenarios. In the framework of the slow-roll approximation we find the expressions for the perturbation…

Astrophysics · Physics 2009-10-28 G. Mangano , G. Miele , C. Stornaiolo

I generalize the inflationary flow equations of Hoffman and Turner to arbitrary order in slow roll. This makes it possible to study the predictions of slow roll inflation in the full observable parameter space of tensor/scalar ratio $r$,…

Astrophysics · Physics 2009-11-07 William H. Kinney

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

We study the dual 3d Euclidean RG flow of single-field slow-roll Inflation using the postulates of the dS/CFT correspondence. For that purpose we solve for the inflationary fluctuation at all times using a matching procedure between two…

High Energy Physics - Theory · Physics 2015-06-17 Uri Kol

The delta N formula that relates the final curvature perturbation on comoving slices to the inflaton perturbation on flat slices after horizon crossing is a powerful and intuitive tool to compute the curvature perturbation spectrum from…

Astrophysics · Physics 2009-10-09 Hyun-Chul Lee , Misao Sasaki , Ewan D. Stewart , Takahiro Tanaka , Shuichiro Yokoyama

Inflation is part of the Standard Model of the Universe supported by CMB and large scale structure LSS datasets. This review presents new developments of inflation in three main chapters. (I): The effective theory of inflation a la…

Cosmology and Nongalactic Astrophysics · Physics 2011-07-13 D. Boyanovsky , C. Destri , H. J. de Vega , N. G. Sanchez

Precise cosmological data from WMAP and forthcoming CMB experiments motivate the study of the quantum corrections to the slowroll inflationary parameters.We find the quantum (loop) corrections to the equations of motion of the classical…

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