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

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We propose new classes of inflation models based on the modular symmetry, where the modulus field $\tau$ serves as the inflaton. We establish a connection between modular inflation and modular stabilization, wherein the modulus field rolls…

High Energy Physics - Phenomenology · Physics 2024-10-21 Gui-Jun Ding , Si-Yi Jiang , Wenbin Zhao

We find multi-scalar effective field theories (EFTs) that can achieve a slow inflationary roll despite having a scalar potential that does not satisfy the usual slow-roll condition (d V)^2 << V^2/Mp^2. They evade the usual slow-roll…

High Energy Physics - Theory · Physics 2016-11-16 Peter Adshead , Diego Blas , C. P. Burgess , Peter Hayman , Subodh P Patil

We discuss the introduction of a non minimal coupling between the inflaton and gravity in terms of the recently proposed $\beta$-function formalism for inflation\cite{Binetruy:2014zya}. Via a field redefinition we reduce to the case of…

High Energy Physics - Phenomenology · Physics 2016-09-27 Mauro Pieroni

In this work we address the reheating issue in the context of $F(R)$ gravity, for theories that the inflationary era does not obey the slow-roll condition but the constant-roll condition is assumed. As it is known, the reheating era takes…

General Relativity and Quantum Cosmology · Physics 2017-10-10 V. K. Oikonomou

We propose the study of constant-roll inflation in $F(R)$ gravity. We use two different approaches, one that relates an $F(R)$ gravity to well known scalar models of constant-roll and a second that examines directly the constant-roll…

General Relativity and Quantum Cosmology · Physics 2017-12-06 S. Nojiri , S. D. Odintsov , V. K. Oikonomou

We show that the cosmological evolution of a scalar field in a potential can be obtained from a renormalisation group equation. The slow roll regime of inflation models is understood in this context as the slow evolution close to a fixed…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-22 P. Binetruy , E. Kiritsis , J. Mabillard , M. Pieroni , C. Rosset

Usual inflation is realized with a slow rolling scalar field minimally coupled to gravity. In contrast, we consider dynamics of a scalar with a flat effective potential, conformally coupled to gravity. Surprisingly, it contains an attractor…

High Energy Physics - Theory · Physics 2008-11-26 Lev Kofman , Shinji Mukohyama

Using the nonlinear $\delta N$ formalism, we consider a simple exactly soluble model of multi-component slow-roll inflation in which the nonlinear curvature perturbation can be evaluated analytically.

Astrophysics · Physics 2008-11-26 Misao Sasaki

We consider low scale slow roll inflation driven by the gauge invariant flat directions {\bf udd} and {\bf LLe} of the Minimally Supersymmetric Standard Model at the vicinity of a saddle point of the scalar potential. We study the stability…

High Energy Physics - Phenomenology · Physics 2010-10-27 Rouzbeh Allahverdi , Kari Enqvist , Juan Garcia-Bellido , Asko Jokinen , Anupam Mazumdar

We study inflation driven by the tachyon field in the holographic braneworld by assuming the second slow-roll parameter $\eta$ is constant. The parameter $\eta$ can be either defined by the tachyon scalar field and the Hubble parameter or…

General Relativity and Quantum Cosmology · Physics 2024-09-16 Marko Stojanovic , Neven Bilic , Dragoljub D. Dimitrijevic , Goran S. Djordjevic , Milan Milosevic

Slow-roll inflation is studied as an effective field theory.We find as consistent form of the inflaton potential V(phi)=N M^4 w(phi/[sqrt{N}M_P]) where phi is the inflaton field, M the inflation energy scale, M_P the Planck mass, and N~50…

Astrophysics · Physics 2009-11-13 D. Boyanovsky , H. J. de Vega , N. G. Sanchez

We report on a new class of fast-roll inflationary models. In a huge part of its parameter space, inflationary perturbations exhibit quite unusual phenomena such as scalar and tensor modes freezing out at widely different times, as well as…

Cosmology and Nongalactic Astrophysics · Physics 2010-04-30 Pascal M. Vaudrevange , Dmitry I. Podolsky , Glenn D. Starkman

Slow-roll inflation can become eternal if the quantum variance of the inflaton field around its slowly rolling classical trajectory is converted into a distribution of classical spacetimes inflating at different rates, and if the variance…

High Energy Physics - Theory · Physics 2017-08-02 Kimberly K. Boddy , Sean M. Carroll , Jason Pollack

The topic of this talk is a new inflationary model in the context of Type IIB string compactifications called Loop Blow-Up Inflation, presented in arXiv:2403.04831. The original Blow-Up Inflation model, whose potential was purely…

High Energy Physics - Theory · Physics 2025-02-24 Luca Brunelli

An inflationary scenario driven by a slow rolling homogeneous scalar field whose potential $V(\Phi)$ is given by a generalized exponential function is discussed. Within the {\sl slow-roll} approximation we investigate some of the main…

Astrophysics · Physics 2008-11-26 J. S. Alcaniz , F. C. Carvalho

Nonminimal coupling of the inflaton field to the Ricci curvature of spacetime is generally unavoidable, and the paradigm of inflation should be generalized by including the corresponding term in the Lagrangian of the inflationary theory.…

High Energy Physics - Theory · Physics 2014-11-18 Valerio Faraoni

Slow-roll inflation is analyzed in the context of modified gravity within the Palatini formalism. As shown in the literature, inflation in this framework requires the presence of non-traceless matter, otherwise it does not occur just as a…

General Relativity and Quantum Cosmology · Physics 2020-11-30 Sabit Bekov , Kairat Myrzakulov , Ratbay Myrzakulov , Diego Sáez-Chillón Gómez

We present an overview of inflationary models derived from string theory focusing mostly on closed string moduli as inflatons. After a detailed discussion of the eta-problem and different approaches to address it, we describe possible ways…

High Energy Physics - Theory · Physics 2015-03-19 Michele Cicoli , Fernando Quevedo

The potential during inflation must be very flat in, at least, the direction of the inflaton. In renormalizable global supersymmetry, flat directions are ubiquitous, but they are not preserved in a generic supergravity theory. It is known…

High Energy Physics - Theory · Physics 2009-09-29 Mary K. Gaillard , David H. Lyth , Hitoshi Murayama

We consider the classical wave equation with a thermal and Starobinsky-Vilenkin noise which in a slow-roll and long wave approximation describes the quantum fluctuations of the graviton-inflaton system in an expanding metric. We investigate…

General Relativity and Quantum Cosmology · Physics 2019-11-13 Z. Haba