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Related papers: Chameleon Field Dynamics During Inflation

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Using a Liouville measure, similar to the one proposed recently by Gibbons and Turok, we investigate the probability that single-field inflation with a polynomial potential can last long enough to solve the shortcomings of the standard hot…

General Relativity and Quantum Cosmology · Physics 2008-11-26 Cristiano Germani , William Nelson , Mairi Sakellariadou

We develop analytic and numerical techniques for studying the statistics of slow-roll inflation in random Gaussian landscapes. As an illustration of these techniques, we analyze small-field inflation in a one-dimensional landscape. We…

High Energy Physics - Theory · Physics 2017-06-14 Ali Masoumi , Alexander Vilenkin , Masaki Yamada

With the growing consensus on simple power law inflation models not being favored by the PLANCK observation, dynamics for the non-standard form of the inflaton potential gain significant interest in the recent past. In this paper, we…

Cosmology and Nongalactic Astrophysics · Physics 2019-02-08 Debaprasad Maity , Pankaj Saha

We investigate the possibility that the inflaton, in particular in conformal inflation models, is also a chameleon, i.e. that it couples to the energy density of some heavy non-relativistic matter present during inflation. We find new and…

High Energy Physics - Theory · Physics 2019-04-24 Heliudson Bernardo , Renato Costa , Horatiu Nastase , Amanda Weltman

Inflationary potentials are investigated for specific models in type IIB string theory via flux compactification. As concrete models, we investigate several cases where the internal spaces are weighted projective spaces. The models we…

High Energy Physics - Theory · Physics 2011-03-15 Sunggeun Lee , Soonkeon Nam

We study a scenario with a transient phase of cosmological acceleration that could potentially be realized in asymptotic corners of String Theory moduli space. A very steep scalar potential is temporarily stabilized by the effect of a…

High Energy Physics - Theory · Physics 2024-06-13 Gonzalo F. Casas , Miguel Montero , Ignacio Ruiz

We develop a numerical statistical method to study linear cosmological fluctuations in inflationary scenarios with multiple fields, and apply it to an ensemble of six-field inflection point models in string theory. The latter are concrete…

Cosmology and Nongalactic Astrophysics · Physics 2012-07-05 Sébastien Renaux-Petel

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 study the six-field dynamics of D3-brane inflation for a general scalar potential on the conifold, finding simple, universal behavior. We numerically evolve the equations of motion for an ensemble of more than 7 \times 10^7 realizations,…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-19 Nishant Agarwal , Rachel Bean , Liam McAllister , Gang Xu

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

The scenario of the slow-roll inflation is studied in the frame of the scalar-tensor theory of gravity where the scalar field has a non-minimal coupling to the geometric part. After deriving the main dynamical and perturbation equations,…

General Relativity and Quantum Cosmology · Physics 2020-12-01 Abolhassan Mohammadi , Tayeb Golanbari , Jamil Enayati , Shahram Jalalzadeh , Khaled Saaidi

In this work, I consider an inflation model with a quadratic potential and a negative cosmological constant. An analytical solution of the equation of motion for the inflaton field is found without slow-roll approximation. The result is…

High Energy Physics - Phenomenology · Physics 2023-04-19 Chia-Min Lin

Making observable predictions for cosmic inflation requires determining when the wavenumbers of astrophysical interest today exited the Hubble radius during the inflationary epoch. These instants are commonly evaluated using the slow-roll…

Cosmology and Nongalactic Astrophysics · Physics 2024-10-17 Pierre Auclair , Baptiste Blachier , Christophe Ringeval

We present an study from PLANCK2013+WP+BAO:$\Lambda$CDM+$r$+$\alpha_s$ data, where 49 slow roll inflationary potentials are tested, showing that the theoretical value of the running provided by 48 of these potentials has a deviation to the…

General Relativity and Quantum Cosmology · Physics 2015-03-24 Jaume Amoros , Jaume de Haro

We study the cosmological inflation from the viewpoint of the moduli stabilization. We study the scenario that the superpotential has a large value during the inflation era enough to stabilize moduli, but it is small in the true vacuum.…

High Energy Physics - Theory · Physics 2015-05-20 Tatsuo Kobayashi , Manabu Sakai

We study inflation in a random multifield potential, using techniques developed by Marsh et al. The potential is a function of a large number of fields, and we choose parameters so that inflation only occurs in regions where the potential…

High Energy Physics - Theory · Physics 2016-08-02 Ben Freivogel , Roberto Gobbetti , Enrico Pajer , I-Sheng Yang

It is very difficult to obtain a realistic model of a closed inflationary universe. Even if one fine-tunes the total number of e-folds to be sufficiently small, the resulting universe typically has large density perturbations on the scale…

Astrophysics · Physics 2009-09-29 Andrei Linde

In this paper we revisit the relationship between the Einstein--Friedman and the Abel equations to demonstrate how it might be applied to the inflationary analysis in a flat Friedman universe filled with a real-valued scalar field. The…

General Relativity and Quantum Cosmology · Physics 2019-07-30 Anna V. Yaparova , Artyom V. Yurov , Valerian A. Yurov

The conventional background solution for the evolution of a single canonical inflaton field performs admirably in extreme scenarios such as the slow-roll phase (where the slow-roll parameter is much less than one) and the deep reheating era…

Cosmology and Nongalactic Astrophysics · Physics 2024-06-26 Manjeet Kaur , Debottam Nandi , Sharath Raghavan B

We obtain cosmological constraints on models of inflation which exhibit rapid roll solutions. Rapid roll attractors exist for potentials with large mass terms and are thus of interest for inflationary model building within string theory. We…

Cosmology and Nongalactic Astrophysics · Physics 2010-04-15 Takeshi Kobayashi , Shinji Mukohyama , Brian A. Powell