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We generalize the Effective Field Theory of Inflation to include additional light scalar degrees of freedom that are in their vacuum at the time the modes of interest are crossing the horizon. In order to make the scalars light in a natural…

High Energy Physics - Theory · Physics 2015-05-19 Leonardo Senatore , Matias Zaldarriaga

Previous work on dynamical black hole instability is further elucidated within the Hamilton-Jacobi method for horizon tunneling and the reconstruction of the classical action by means of the null-expansion method. Everything is based on two…

General Relativity and Quantum Cosmology · Physics 2015-05-13 Roberto Di Criscienzo , Sean A. Hayward , Mario Nadalini , Luciano Vanzo , Sergio Zerbini

We consider inflation in the system containing a Ricci scalar squared term and a canonical scalar field with quadratic mass term. In the Einstein frame this model takes the form of a two-field inflation model with a curved field space, and…

Cosmology and Nongalactic Astrophysics · Physics 2017-11-01 Taro Mori , Kazunori Kohri , Jonathan White

We use transport techniques to calculate the trispectrum produced in multiple-field inflationary models with canonical kinetic terms. Our method allows the time evolution of the local trispectrum parameters, tauNL and gNL, to be tracked…

Cosmology and Nongalactic Astrophysics · Physics 2012-10-23 Gemma J. Anderson , David J. Mulryne , David Seery

We completely clarify the feature of primordial non-Gaussianities of tensor perturbations in generalized G-inflation, i.e., the most general single-field inflation model with second order field equations. It is shown that the most general…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Xian Gao , Tsutomu Kobayashi , Masahide Yamaguchi , Jun'ichi Yokoyama

Within the framework of hybrid metric-Palatini gravity, we incorporate non-localities introduced via the inverse of the d'Alembert operators acting on the scalar curvature. We analyse the dynamical structure of the theory and, adopting a…

High Energy Physics - Theory · Physics 2025-05-16 Flavio Bombacigno , Mariaveronica De Angelis , Carsten van de Bruck , William Giarè

The bispectrum of scalar mode density perturbations is analysed for the strong regime of warm inflationary models. This analysis generalises previous results by allowing damping terms in the inflaton equation of motion that are dependent on…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-27 Ian G Moss , Timothy Yeomans

We study the impact of higher dimension operators in the inflaton Lagrangian on the non-gaussianity of the scalar spectrum. These terms can strongly enhance the effect without spoiling slow-roll, though it is difficult to exceed f_NL ~ 1,…

Astrophysics · Physics 2011-05-05 Paolo Creminelli

Inflation is an early period of accelerated cosmic expansion, thought to be sourced by high energy physics. A key task today is to use the influx of increasingly precise observational data to constrain the plethora of inflationary models…

Cosmology and Nongalactic Astrophysics · Physics 2013-08-05 Joseph Elliston

We revisit the time evolution of a flat and non-flat direction system during inflation. In order to take into account quantum noises in the analysis, we base on stochastic formalism and solve coupled Langevin equations numerically. We focus…

High Energy Physics - Phenomenology · Physics 2015-06-05 Masahiro Kawasaki , Tomohiro Takesako

In this paper we calculate additional contributions to that part of the non-Gaussianity of the curvature perturbation, which come from the three-point correlator of the field perturbations. We estimate this contribution in the following…

Astrophysics · Physics 2007-05-23 Ignacio Zaballa , Yeinzon Rodriguez , David H. Lyth

We develop a theory of nonlinear cosmological perturbations on superhorizon scales for generic single-field inflation. Our inflaton is described by the Lagrangian of the form $W(X,\phi)-G(X,\phi)\Box\phi$ with…

General Relativity and Quantum Cosmology · Physics 2013-06-04 Yu-ichi Takamizu , Tsutomu Kobayashi

The inflation model with non-minimal coupling scalar field in the context of the hybrid metric Palatini is studied in this paper. We derive the Einstein's field equations, the equations of motion of the scalar field. Furthermore,the…

General Relativity and Quantum Cosmology · Physics 2024-02-29 Brahim Asfour , Aatifa Bargach , Ahmed Errahmani , Taoufik Ouali

We construct models of inflation with many randomly interacting fields and use these to study the generation of cosmological observables. We model the potentials as multi-dimensional Gaussian random fields (GRFs) and identify powerful…

Cosmology and Nongalactic Astrophysics · Physics 2018-02-28 Theodor Bjorkmo , M. C. David Marsh

We study perturbations in the multi-field axion Nflation model, taking account of the full cosine potential. We find significant differences with previous analyses which made a quadratic approximation to the potential. The tensor-to-scalar…

Cosmology and Nongalactic Astrophysics · Physics 2015-03-17 Soo A Kim , Andrew R Liddle , David Seery

The Cosmic Microwave Background can provide information regarding physics of the very early universe, more specifically, of the matter-radiation distribution of the inflationary era. Starting from the effective field theory of inflation, we…

High Energy Physics - Theory · Physics 2015-09-02 Anindya Banerjee , Himanshu Khanchandani

Non-abelian gauge field inflation is studied in the context of warm inflation scenario. We introduce this scenario as a mechanism that gives an end for gauge-flation model. Slow-roll parameters and perturbation parameters are presented for…

General Relativity and Quantum Cosmology · Physics 2015-06-17 M. R. Setare , V. Kamali

Models of inflation where the entropic directions have large and negative masses $|m_s| \gg H$ can be well described by a single-field EFT with an imaginary sound speed $c_s$. Among other features, they predict an exponential enhancement of…

Cosmology and Nongalactic Astrophysics · Physics 2020-08-19 Ricardo Z. Ferreira

We consider the possibility to observationally differentiate the Standard Model (SM) Higgs driven inflation with non-minimal couplingto gravity from other variants of SM Higgs inflation based on the scalar field theories with non-canonical…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-28 L. A. Popa

Non-linear interactions during inflation generate non-Gaussianities in the distribution of primordial curvature. In many theories, the physics is scale-invariant, such that the induced three-point function depends solely on a dimensionless…

Cosmology and Nongalactic Astrophysics · Physics 2026-03-27 Oliver H. E. Philcox