English
Related papers

Related papers: Initial Conditions for Inflation - A Short Review

200 papers

We develop a consistent analytic approach to determine the conditions under which slow roll inflation can arise when the inflaton is the same scalar field that is responsible for the bounce in Loop Quantum Cosmology (LQC). We find that the…

General Relativity and Quantum Cosmology · Physics 2019-11-04 Anshuman Bhardwaj , Edmund J. Copeland , Jorma Louko

We discuss how initial conditions for cosmological evolution can be defined in Loop Quantum Cosmology with massive scalar field and how the presence of the bounce influences the probability of inflation in this theory, compared with General…

General Relativity and Quantum Cosmology · Physics 2019-02-15 Suzana Bedić , Gregory Vereshchagin

We explore the inflationary phase of a scalar field with a kinetic term non-minimally coupled to gravity. We find that one of the slow-roll conditions is naturally consequence of the equation of motion of the scalar field. Thus, slow-roll…

Cosmology and Nongalactic Astrophysics · Physics 2014-09-16 Amir Ghalee

We propose a scenario of the beginning of inflation in which the non-vacuum value of the scalar field that drives inflation develops dynamically due to the non-minimal coupling to gravity. In this scenario, inflation emerges as an…

High Energy Physics - Phenomenology · Physics 2016-09-06 M. V. Libanov , V. A. Rubakov , P. G. Tinyakov

We investigate the initial conditions of inflation in a Bianchi~I universe that is homogeneous but not isotropic. We use the Eisenhart lift to describe such a theory geometrically as geodesics on a field space manifold. We construct the…

General Relativity and Quantum Cosmology · Physics 2020-03-18 Kieran Finn

Many different models of inflation give rise to the same effective field theory of the inflaton. While effective field theories in flat space provide little information about UV physics, we propose that in inflationary backgrounds a large…

High Energy Physics - Theory · Physics 2012-01-04 Ross O'Connell , R. Holman

In the context of inflationary models with a pre-inflationary stage, in which the Einstein equations are obeyed, the weak energy condition is satisfied, and spacetime topology is trivial, we argue that homogeneity on super-Hubble scales…

General Relativity and Quantum Cosmology · Physics 2009-10-31 Tanmay Vachaspati , Mark Trodden

We consider the torsional completion of gravity with spinor and scalar fields: we show how in this environment conditions of extreme symmetry or specific approximations imply the scalar field to be constant, so that slow-roll takes place…

General Relativity and Quantum Cosmology · Physics 2017-07-07 Luca Fabbri

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

We show that in the simplest theories of spontaneous symmetry breaking one can have a stage of a fast-roll inflation. In this regime the standard slow-roll condition |m^2| << H^2 is violated. Nevertheless, this stage can be rather long if…

High Energy Physics - Theory · Physics 2009-11-07 Andrei Linde

We study the possibility that inflation is driven by a scalar field together with a vector field minimally coupled to gravity. By assuming an effective potential that incorporates both fields into the action, we explore two distinct…

General Relativity and Quantum Cosmology · Physics 2024-12-09 Manuel Gonzalez-Espinoza , Ramon Herrera

In this paper we investigate the asymptotic dynamics of inflationary cosmological models that are based in scalar-tensor theories of gravity. Our main aim is to explore the global structure of the phase space in the framework of…

General Relativity and Quantum Cosmology · Physics 2020-05-20 Israel Quiros , Tame Gonzalez , Roberto De Arcia , Ricardo García-Salcedo , Ulises Nucamendi , Joel F. Saavedra

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

String theory gives rise to various mechanisms to generate primordial inflation, of which ``brane inflation'' is one of the most widely considered. In this scenario, inflation takes place while two branes are approaching each other, and the…

High Energy Physics - Theory · Physics 2009-11-10 R. Brandenberger , G. Geshnizjani , S. Watson

Inflation in cosmology is a specific stage preceding the Big Bang, aimed at solving both old background problems and new perturbation issues. Single-field inflation is a candidate to illustrate the picture of the initial universe, and…

Cosmology and Nongalactic Astrophysics · Physics 2025-05-21 Guanqiao Liu

The inflationary scenario is not the only paradigm of early universe cosmology which is consistent with current observations. General criteria will be presented which any successful early universe model must satisfy. Various ways, including…

High Energy Physics - Theory · Physics 2018-09-14 Robert H. Brandenberger

An introductory account is given of the inflationary cosmology, which postulates a period of accelerated expansion during the Universe's earliest stages. The historical motivation is briefly outlined, and the modelling of the inflationary…

Astrophysics · Physics 2007-05-23 Andrew R Liddle

We investigate in detail the attractor behavior of some inflationary models based on braneworld dynamics under the constant-roll condition. We describe the dynamics of the models, assuming that the second slow-roll parameter remains…

General Relativity and Quantum Cosmology · Physics 2025-04-29 Goran S. Djordjevic , Neven Bilić , Dragoljub D. Dimitrijevic , Milan Milosevic , Marko Stojanovic

A brief account is given of large-scale structure modelling based on the assumption that the initial perturbations arise from inflation. A recap is made of the implications of inflation for large-scale structure; under the widely applicable…

Astrophysics · Physics 2007-05-23 Andrew R Liddle

After a brief summary of general relativity and cosmology, we present the basic concepts underlying inflation, the currently best motivated models for the early Universe. We describe the simplest inflation models, based on a single scalar…

General Relativity and Quantum Cosmology · Physics 2008-11-27 David Langlois