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An alternative inflationary model is proposed predicated upon a consideration of the form of the uncertainty principle in a curved background spacetime. An argument is presented suggesting a possible curvature dependence in the correct…

General Relativity and Quantum Cosmology · Physics 2014-05-12 Paul J. Camp , John L. Safko

How much does the curvature perturbation change after it leaves the horizon, and when should one evaluate the power spectrum? To answer these questions we study single field inflation models numerically, and compare the evolution of…

Cosmology and Nongalactic Astrophysics · Physics 2013-02-26 Ellie Nalson , Adam J. Christopherson , Ian Huston , Karim A. Malik

Recently, it was proposed that a small true vacuum universe can inflate spontaneously, in principle. Furthermore, there should be matter creation in vacuum inflation due to quantum fluctuations, and the matter created will influence the…

General Relativity and Quantum Cosmology · Physics 2017-05-01 Zhiqiang Huang , Dongfeng Gao , Qing-yu Cai

Eternal inflation is studied in the context of warm inflation. We focus on different tools to analyze the effects of dissipation and the presence of a thermal radiation bath on the fluctuation-dominated regime, for which the…

Cosmology and Nongalactic Astrophysics · Physics 2016-03-14 Gustavo S. Vicente , Leandro A. da Silva , Rudnei O. Ramos

Motivated by trans-Planckian issues in inflation, we determine the Hilbert space and amplitudes of quantum perturbations in the general low-energy effective theory of (multi-)field inflation without relying on the sub-horizon limit. The…

High Energy Physics - Theory · Physics 2026-05-29 Andrea Ambrosi de Magistris , Alberto Salvio

We draw a figure from where it is possible to measure the number of e-folds of expansion of the universe with a ruler. We find model independent bounds for the number of e-folds during inflation, reheating and radiation. We also give a…

Cosmology and Nongalactic Astrophysics · Physics 2020-05-26 Gabriel German

In this paper we present a model for accelerated expansion of the universe, both during inflation and the present stage of the expansion, from four dimensional $\mathcal{N}=1$ supergravity. We evaluate the tensor-to-scalar ratio ($r\approx…

High Energy Physics - Theory · Physics 2015-09-29 Ricardo C. G. Landim

Out-of-equilibrium, non-perturbative, quantum effects significantly modify the standard picture of inflation in a wide class of models including new, natural, and hybrid inflation. We find that the quantum evolution of a single real…

High Energy Physics - Phenomenology · Physics 2010-01-06 D. Cormier , R. Holman

We show that models of inflection point inflation exhibit a phase transition from a region in parameter space where they are of large field type to a region where they are of small field type. The phase transition is between a universal…

High Energy Physics - Theory · Physics 2009-06-25 Nissan Itzhaki , Ely D. Kovetz

I present a brief review of astro-ph/0406099, which argues that there is a limit on the number of efolds of inflation which are observable in a universe which undergoes an eternally accelerated expansion in the future. Such an acceleration…

High Energy Physics - Theory · Physics 2007-05-23 Matthew Kleban

We investigate the dynamical properties of a class of spatially homogeneous and isotropic cosmological models containing a barotropic perfect fluid and multiple scalar fields with independent exponential potentials. We show that the…

General Relativity and Quantum Cosmology · Physics 2009-10-31 A. A. Coley , R. J. van den Hoogen

In the present work we study the consequences of considering an inflationary universe model in which the Hubble rate has a quasi-exponential dependence in the inflaton field, given by $H(\phi)=H_{inf}\exp…

General Relativity and Quantum Cosmology · Physics 2017-04-05 Nelson Videla

We investigate the quantum fluctuations of an inflaton field in a two-field model of one-bubble open inflation. One of the inflatons is assumed to be responsible for the first false vacuum stage of inflation and the other is assumed to be…

Astrophysics · Physics 2009-10-09 Misao Sasaki , Takahiro Tanaka

Inflation models can have an early phase of inflation where the evolution of the inflaton is driven by quantum fluctuations before entering the phase driven by the slope of the scalar field potential. For a Coleman-Weinberg potential this…

Cosmology and Nongalactic Astrophysics · Physics 2013-03-06 Arjun Berera , Raghavan Rangarajan

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

A bidimensional parameter space of unitary area is introduced to study phenomenologically the dynamic and thermodynamic behavior of inflationary models driven by a scalar field coupled to a thermal component. In this enlarged context the…

Astrophysics · Physics 2010-01-06 J. M. F. Maia , J. A. S. Lima

We compute the distribution of sizes of inflating and non-inflating regions in an eternally inflating Universe. As a first illustrative problem, we study a simple scenario of an eternally inflating Universe in the presence of a massless…

Cosmology and Nongalactic Astrophysics · Physics 2019-08-15 Mudit Jain , Mark P. Hertzberg

Currently, a method has been developed for the cosmological inflation model with a single scalar field to calculate cosmological parameters such as the power spectrum of scalar and tensor perturbations, their spectral indices, and the…

General Relativity and Quantum Cosmology · Physics 2025-01-06 Katerina Bolshakova , Sergey Chervon

Using the fact that we only observe those modes which exit the Hubble horizon during inflation, one can calculate the entanglement entropy of such long-wavelength perturbations by tracing out unobservable sub-Hubble fluctuations they are…

High Energy Physics - Theory · Physics 2022-06-14 Suddhasattwa Brahma

We reexamine inflation due to a constrained inflaton in the model of a complex scalar. Inflaton evolves along a spiral-like valley of special scalar potential in the scalar field space just like single field inflation. Sub-Planckian…

High Energy Physics - Phenomenology · Physics 2015-12-02 Romy H. S. Budhi , Shoichi Kashiwase , Daijiro Suematsu