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Following the recent Atacama Cosmology Telescope (ACT) results, we consider hilltop inflation where the inflaton is coupled to a curvaton, simultaneously addressing two main challenges faced by conventional hilltop inflation models: the…

High Energy Physics - Phenomenology · Physics 2026-05-12 Wen-Yuan Ai , Stephen F. King , Xin Wang , Ye-Ling Zhou

We investigate if the observed small and nearly scale-invariant primordial cosmic perturbation, i.e. the perturbation amplitude $P_\zeta\sim10^{-9}$ and the spectral index $n_s \simeq 0.965$, is typical in the landscape of vacua after…

Cosmology and Nongalactic Astrophysics · Physics 2019-07-17 Chien-I Chiang , Keisuke Harigaya

In most current models of inflation based on a weakly self-coupled scalar matter field minimally coupled to gravity, the period of inflation lasts so long that, at the beginning of the inflationary period, the physical wavelengths of…

High Energy Physics - Theory · Physics 2008-11-26 Jerome Martin , Robert H. Brandenberger

Using numerical solutions of the full Einstein field equations coupled to a scalar inflaton field in 3+1 dimensions, we study the conditions under which a universe that is initially expanding, highly inhomogeneous and dominated by gradient…

High Energy Physics - Theory · Physics 2016-09-07 William E. East , Matthew Kleban , Andrei Linde , Leonardo Senatore

We perform a numerical investigation of the fields evolution in the supersymmetric inflationary model based on radiative corrections. Supergravity corrections are also included. We find that, out of all the examined initial data, only about…

High Energy Physics - Phenomenology · Physics 2008-11-26 G. Lazarides , N. D. Vlachos

Recently, a model of inflation using non-minimally coupled massive vector fields has been proposed. For a particular choice of non-minimal coupling parameter and for a flat FRW model, the model is reduced to the model of chaotic inflation…

General Relativity and Quantum Cosmology · Physics 2014-11-18 Takeshi Chiba

The leading account of several salient observable features of our universe today is provided by the theory of cosmic inflation. But an important and thus far intractable question is whether inflation is generic, or whether it is finely…

History and Philosophy of Physics · Physics 2019-11-14 Feraz Azhar

Most models of inflation have small parameters, either to guarantee sufficient inflation or the correct magnitude of the density perturbations. In this paper we show that, in supersymmetric theories with weak scale supersymmetry breaking,…

High Energy Physics - Phenomenology · Physics 2009-09-15 Lisa Randall , Marin Soljacic , Alan Guth

It has been shown that hybrid inflation may end with the formation of non-topological solitons of inflaton field. As a first step towards a fully realistic picture of the post-inflation era and reheating in supersymmetric hybrid inflation…

High Energy Physics - Phenomenology · Physics 2009-11-10 Matt Broadhead , John McDonald

We analyse the dynamics of spinodal decomposition in inflationary cosmology using the closed time path formalism of out of equilibrium quantum field theory combined with the non-perturbative Hartree approximation. In addition to a general…

High Energy Physics - Phenomenology · Physics 2009-10-31 D. Cormier , R. Holman

We adopt the double field natural inflation model motivated by the non-perturbative effects of supergravity and superstring theory to do the slow roll analysis. We show that when the parameters are suitably chosen, there exist ranges of…

General Relativity and Quantum Cosmology · Physics 2019-04-12 Ping Kwan Man Ellgan

Cosmological magnetic fields pervade the entire universe, from small to large scales. Since they apparently extend into the intergalactic medium, it is tantalizing to believe that they have a primordial origin, possibly being produced…

High Energy Physics - Theory · Physics 2015-06-23 Gianmassimo Tasinato

While cosmological inflation can erase primordial inhomogeneities, it is possible that inflation may not begin in a significantly inhomogeneous universe. This issue is particularly pressing in multifield scenarios, where even the…

Cosmology and Nongalactic Astrophysics · Physics 2014-08-25 Richard Easther , Layne C. Price , Javier Rasero

Cosmic inflation is arguably the most favoured paradigm of the very early Universe. It postulates an early phase of fast, nearly exponential, and accelerated expansion. Inflationary models are capable of explaining the overall flatness and…

Cosmology and Nongalactic Astrophysics · Physics 2022-11-08 Cristian Joana

Models of cosmic inflation suggest that our universe underwent an early phase of accelerated expansion, driven by the dynamics of one or more scalar fields. Inflationary models make specific, quantitative predictions for several observable…

Cosmology and Nongalactic Astrophysics · Physics 2016-05-10 David I. Kaiser

In order to draw out the essential behavior of the universe, investigations of early universe cosmology often reduce the complex system to a simple integrable system. Inflationary models are of this kind as they focus on simple scalar field…

Astrophysics · Physics 2009-10-28 Neil J. Cornish , Janna J. Levin

In this paper, we investigate the evolution of the early universe within an emergent fractional cosmological framework. The underlying formulation is conceptually rooted in generalized measure constructions, closely related to fractal…

General Relativity and Quantum Cosmology · Physics 2026-04-16 S. M. M. Rasouli

In the context of single field inflation, models with a quadratic potential and models with a natural potential with subplanckian decay constant are in tension with the Planck data. We show that, when embedded in a two-field model with an…

Cosmology and Nongalactic Astrophysics · Physics 2015-07-15 Ana Achucarro , Vicente Atal , Yvette Welling

Inflationary cosmology proposes that the early Universe undergoes accelerated expansion, driven, in simple scenarios, by a single scalar field, or inflaton. The form of the inflaton potential determines the initial spectra of density…

Cosmology and Nongalactic Astrophysics · Physics 2022-09-21 Richard Easther , Benedict Bahr-Kalus , David Parkinson

We consider the classical evolution of the inflaton field $\phi(t)$ and the Hubble parameter $H(t)$ in homogeneous and isotropic single-field inflation models. Under an extremely broad assumption, we show that the universe generically…

Cosmology and Nongalactic Astrophysics · Physics 2018-09-19 W. J. Handley , S. D. Brechet , A. N. Lasenby , M. P. Hobson