English
Related papers

Related papers: Anisotropic inflation in Brans-Dicke gravity

200 papers

In the framework of inflation, scales which nowadays correspond to large scale structures were smaller than the Planck length at the beginning of inflation. Therefore, measurements of CMBR anisotropy or surveys of galaxies and of clusters…

Astrophysics · Physics 2007-05-23 Jerome Martin , Robert H. Brandenberger

We develop a formalism for calculating cosmic microwave background (CMB) temperature and polarization anisotropies in cosmological models with Brans-Dicke gravity. We then modify publicly available Boltzmann codes to calculate numerically…

Astrophysics · Physics 2008-11-26 Xuelei Chen , Marc Kamionkowski

We propose a model for cosmic inflation which is based on an effective description of strongly interacting, nonsupersymmetric matter within the framework of dynamical abelian projection and centerization. The underlying gauge symmetry is…

High Energy Physics - Phenomenology · Physics 2007-05-23 Ralf Hofmann , Mathias Th. Keil

Constant roll inflation is analyzed in the presence of multi scalar fields which are assumed to be described by a constant roll rate each. The different cases are studied and the corresponding potentials are reconstructed. The exact…

General Relativity and Quantum Cosmology · Physics 2021-01-04 Merce Guerrero , Diego Rubiera-Garcia , Diego Saez-Chillon Gomez

The behaviour of a non-canonical scalar field within an anisotropic Bianchi type I, spatially homogeneous, Universe in the framework of the intermediate inflation will be studied. It will be examined on the condition that both the…

General Physics · Physics 2019-08-19 Mahdeyeh Naderi , Ali Aghamohammadi , Abdollah Refaei , Haidar Sheikhahmadi

We obtain observational constraints on Randall--Sundrum type II braneworld inflation using a compilation of data including WMAP, the 2dF and latest SDSS galaxy redshift surveys. We place constraints on three classes of inflation models…

Astrophysics · Physics 2014-10-13 Shinji Tsujikawa , Andrew R. Liddle

We review an inflationary scenario with the anisotropic expansion rate. An anisotropic inflationary universe can be realized by a vector field coupled with an inflaton, which can be regarded as a counter example to the cosmic no-hair…

High Energy Physics - Theory · Physics 2015-06-04 Jiro Soda

We derive some new constraints on single-field inflation from the Wilkinson Microwave Anisotropy Probe 3-year data combined with the Sloan Luminous Red Galaxy survey. Our work differs from previous analyses by focusing only on the…

Astrophysics · Physics 2008-11-26 Julien Lesgourgues , Wessel Valkenburg

We show that deviations of the quantum state of the inflaton from the thermal vacuum of inflation may leave an imprint in the CMB anisotropies. The quantum dynamics of the inflaton in such a state produces corrections to the inflationary…

High Energy Physics - Theory · Physics 2009-11-10 Nemanja Kaloper , Manoj Kaplinghat

In this paper, we investigate the back-reaction of $U(1)$ gauge fields into a class of inflationary settings. To be more precise, we employ a Bianchi-I geometry (taken as an anisotropic perturbation of a flat FRW model) within two types of…

General Relativity and Quantum Cosmology · Physics 2011-03-28 Paulo Vargas Moniz , John Ward

We have studied the paradigm of cosmic inflation using the simplest model based on the idea of supersymmetric hybrid inflation with non-minimal coupling to gravity, specially under the slow-roll approximation following the superconformal…

Cosmology and Nongalactic Astrophysics · Physics 2020-01-22 Umananda Dev Goswami

In this paper, we study the complexity factor of a static anisotropic sphere in the context of self-interacting Brans-Dicke theory. We split the Riemann tensor using Bel's approach to obtain structure scalars relating to comoving congruence…

General Relativity and Quantum Cosmology · Physics 2019-10-23 M. Sharif , Amal Majid

Slow-roll inflation is studied in theories where the inflaton field is conformally coupled to the Ricci scalar. In particular, the case of Higgs field inflation in the context of the noncommutative spectral action is analyzed. It is shown…

High Energy Physics - Theory · Physics 2010-08-31 Michel Buck , Malcolm Fairbairn , Mairi Sakellariadou

We explore the dynamics of multi-field models of inflation in which the field-space metric is a hyperbolic manifold of constant curvature. Such models are known as $\alpha$-attractors and their single-field regimes have been extensively…

High Energy Physics - Theory · Physics 2021-12-14 Perseas Christodoulidis , Diederik Roest , Evangelos I. Sfakianakis

It is known that power-law k-inflation can be realized for the Lagrangian $P=Xg(Y)$, where $X=-(\partial \phi)^2/2$ is the kinetic energy of a scalar field $\phi$ and $g$ is an arbitrary function in terms of $Y=Xe^{\lambda \phi/M_{pl}}$…

High Energy Physics - Theory · Physics 2013-11-18 Junko Ohashi , Jiro Soda , Shinji Tsujikawa

Non-adiabatic pressure perturbations naturally occur in models of inflation consisting of more than one scalar field. The amount of non-adiabatic pressure present at the end of inflation can have observational consequences through changes…

Cosmology and Nongalactic Astrophysics · Physics 2012-11-30 Ian Huston , Adam J. Christopherson

In this paper, we investigate the validity of the so-called cosmic no-hair conjecture in the framework of anisotropic inflation models of non-canonical scalar fields non-minimally coupled to a two-form field. In particular, we focus on two…

General Relativity and Quantum Cosmology · Physics 2024-02-06 Tuyen M. Pham , Duy H. Nguyen , Tuan Q. Do , W. F. Kao

The possibility of having an inflationary epoch within a noncommutative geometry approach to unifying gravity and the standard model is demonstrated. This inflationary phase occurs without the need to introduce "ad hoc" additional fields or…

High Energy Physics - Theory · Physics 2010-01-26 William Nelson , Mairi Sakellariadou

We study an inflation model driven by a triplet of antisymmetric tensor fields, with minimal and nonminimal couplings to gravity. First, we show that the presence of a triplet of antisymmetric tensor fields can provide inherent background…

General Relativity and Quantum Cosmology · Physics 2025-09-12 Abhijith Ajith , Sukanta Panda

Inflation generates gravitational waves, which may be observable in the low multipoles of the cosmic microwave background (cmb) anisotropy but only if the inflaton field variation is at least of order the Planck scale. Such a large…

High Energy Physics - Phenomenology · Physics 2009-10-28 David H. Lyth