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Related papers: Large-$\eta$ Constant-Roll Inflation Is Never An A…

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In this work, we systematically present a new dynamical systems approach to standard inflationary processes and their variants as constant-roll inflation. Using the techniques presented in our work one can in general investigate the…

General Relativity and Quantum Cosmology · Physics 2026-01-13 Sandip Biswas , Saddam Hussain , Kaushik Bhattacharya

In this work we shall investigate the phenomenological implications of the constant-roll condition on a $k$-Inflation theory of gravity. The latter theories are particularly promising, since these remained robust to the results of GW170817,…

General Relativity and Quantum Cosmology · Physics 2020-01-29 S. D. Odintsov , V. K. Oikonomou

In this work we study slow-roll inflation for a vector-tensor model with massive vector fields non-minimally coupled to gravity. The model under consideration has arbitrary parameters for each geometrical coupling. Taking into account a…

General Relativity and Quantum Cosmology · Physics 2016-12-21 A. Oliveros

Many models of inflation driven by vector fields alone have been known to be plagued by pathological behaviors, namely ghost and/or gradient instabilities. In this work, we seek a new class of vector-driven inflationary models that evade…

High Energy Physics - Theory · Physics 2017-04-05 Razieh Emami , Shinji Mukohyama , Ryo Namba , Ying-li Zhang

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

We derive consistency conditions for sustained slow roll and rapid turn inflation in two-field cosmological models with oriented scalar field space, which imply that inflationary models with field-space trajectories of this type are…

High Energy Physics - Theory · Physics 2023-05-18 Lilia Anguelova , Calin Iuliu Lazaroiu

In this work, we explore the prospect of generalizing the constant-roll condition in canonical inflationary model to non-canonical models. To find a natural generalization, we focus on three manifestations of this condition and construct…

General Relativity and Quantum Cosmology · Physics 2024-05-07 S. Mohammad Ahmadi , Nahid Ahmadi , Mehdi Shokri

We consider non-canonical generalizations of two classes of simple single-field inflation models. First, we study the non-canonical version of "ultra-slow roll" inflation, which is a class of inflation models for which quantum modes do not…

Astrophysics · Physics 2009-11-13 Konstantinos Tzirakis , William H. Kinney

In the present paper, we aim to generalize the constant-roll inflation in the non-canonical set-up, particularly in the context of scalar Dirac-Born-Infeld (DBI) theory which has emerged to be prospective candidate for describing inflation…

High Energy Physics - Theory · Physics 2018-07-05 Sayantani Lahiri

We present the model-independent studies of non attractor inflation in the context of effective field theory (EFT) of inflation. Within the EFT approach two independent branches of non-attractor inflation solutions are discovered in which a…

High Energy Physics - Theory · Physics 2015-08-06 Mohammad Akhshik , Hassan Firouzjahi , Sadra Jazayeri

Using the constant-roll approach, DBI inflationary scenario will be studied and it is sought to compare the result with observational data. By considering the cosmological perturbations of the model, it is realized that some extra terms…

General Relativity and Quantum Cosmology · Physics 2020-05-12 Abolhassan Mohammadi , Tayeb Golanbari , Khaled Saaidi

We examine the dynamics of inflation driven by multiple, interacting scalar fields and derive a multi field version of the Hubble slow roll expansion. We show that the properties of this expansion naturally generalize those of the single…

Astrophysics · Physics 2013-05-29 Richard Easther , John T Giblin

We consider the constant-roll condition in the model of the inflaton nonminimal coupling to the Gauss-Bonnet term. By assuming the first Gauss-Bonnet flow parameter $\delta_1$ is a constant, we discuss the constant-roll inflation with…

General Relativity and Quantum Cosmology · Physics 2020-12-02 Tie-Jun Gao

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 present a non-perturbative framework for the dynamics of slow-roll inflation that consistently incorporates quantum corrections, based on an alternative functional renormalisation group (RG) approach. We derive the coupled Friedmann-RG…

High Energy Physics - Theory · Physics 2025-11-10 Jean Alexandre , Lucien Heurtier , Silvia Pla

Slow-roll of the inflaton field defines the standard dynamics of the inflationary epoch. However, the inflationary system deviates from slow-roll when it encounters an extremely flat region of the inflaton potential, and enters a phase…

Cosmology and Nongalactic Astrophysics · Physics 2024-01-04 Sandip Biswas , Kaushik Bhattacharya , Suratna Das

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

Inspired by the Generalized Proca Theory, we study a vector-tensor model of inflation with massive vector fields and derivative self-interactions. The action under consideration contains a usual Maxwell-like kinetic term, a general…

General Relativity and Quantum Cosmology · Physics 2019-03-15 A. Oliveros , Marcos A. Jaraba

The constant-roll inflation with small positive value of the constant-roll parameter $\beta\equiv \frac{\ddot\phi}{H\dot\phi}={\rm const.}$ has been known to produce a slightly red-tilted curvature power spectrum compatible with the current…

General Relativity and Quantum Cosmology · Physics 2020-04-21 Hayato Motohashi , Shinji Mukohyama , Michele Oliosi

A supersymmetric inflationary stage dominated by an $F$-term has the problem that the flatness of the potential is spoiled by supergravity corrections, that is the slow-roll parameter $\eta$ gets contributions of order unity. We show that…

High Energy Physics - Phenomenology · Physics 2009-10-31 J. A. Casas , G. B. Gelmini , A. Riotto