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Curvature perturbations generated after the end of inflation are estimated for a generic multi-field inflationary potential. The curvature perturbations are generated by conversion of inflationary isocurvature perturbations, similar to…

Astrophysics · Physics 2007-05-23 Andrei Gruzinov

We discuss the signatures of non-Gaussianity in the curvaton model where the potential includes also a non-quadratic term. In such a case the non-linearity parameter f_NL can become very small, and we show that non-Gaussianity is then…

Astrophysics · Physics 2011-07-13 Kari Enqvist , Tomo Takahashi

Inflation may occur while rolling into the metastable supersymmetry-breaking vacuum of massive supersymmetric QCD. We explore the range of parameters in which slow-roll inflation and long-lived metastable supersymmetry breaking may be…

High Energy Physics - Theory · Physics 2008-11-26 Nathaniel J. Craig

In [1], a most general higher curvature non-local gravity action was derived that admits a particular $R^2$-like inflationary solution predicting the spectral index of primordial scalar perturbations $n_s(N)\approx 1-\frac{2}{N}$, where $N$…

High Energy Physics - Theory · Physics 2023-07-18 Alexey S. Koshelev , K. Sravan Kumar , Alexei A. Starobinsky

We investigate the non-Gaussianities of inflation driven by a single scalar field coupling non-minimally to the Einstein Gravity. We assume that the form of the scalar field is very general with an arbitrary sound speed. For convenience to…

High Energy Physics - Theory · Physics 2011-05-27 Taotao Qiu , Kwei-Chou Yang

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

[Abridged] In this paper we explore a local non-linear perturbative model up to third order as a general characterization of the CMB anisotropies. We focus our analysis in large scale anisotropies. At these angular scales, the non-Gaussian…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-14 P. Vielva , J. L. Sanz

We compute the 3-point correlation function for a general model of inflation driven by a single, minimally coupled scalar field. Our approach is based on the numerical evaluation of both the perturbation equations and the integrals which…

Astrophysics · Physics 2010-10-27 Xingang Chen , Richard Easther , Eugene A. Lim

We study the planar regime of curvature perturbations for single field inflationary models in an axially symmetric Bianchi I background. In a theory with standard scalar field action, the power spectrum for such modes has a pole as the…

High Energy Physics - Theory · Physics 2014-06-13 Anindya Dey , Ely D. Kovetz , Sonia Paban

We analyse the situation where the primordial curvature perturbations are produced by the joint effects of an inflaton field and two curvaton fields. We present general equations which allow the reader to obtain f_NL for several different…

Cosmology and Nongalactic Astrophysics · Physics 2013-03-14 Maria Sueiro , Malcolm Fairbairn

We investigate the inflaton decay and reheating period after the end of inflation in the non-minimal derivative coupling (NDC) model with chaotic potential. In general, this model is known to provide an enhanced slow-roll inflation caused…

General Relativity and Quantum Cosmology · Physics 2016-07-20 Yun Soo Myung , Taeyoon Moon

Using the \delta N formalism we consider the non-linear curvature perturbation in multi-field models of inflation with non-minimal coupling. In particular, we focus on the relation between the \delta N formalism as applied in the…

Cosmology and Nongalactic Astrophysics · Physics 2013-09-25 Jonathan White , Masato Minamitsuji , Misao Sasaki

We consider the nonlinear dynamics of inflaton fragmentation during and after preheating in the simplest model of chaotic inflation. While the earlier regime of parametric resonant particle production and the later turbulent regime of…

High Energy Physics - Phenomenology · Physics 2008-11-26 Gary N. Felder , Lev Kofman

In the present work we study a warm inflationary model defined by a quasi-exponential inflaton potential and an inflaton decay rate proportional to the Hubble rate. The model is characterized by three free parameters. We compute the power…

General Relativity and Quantum Cosmology · Physics 2018-06-13 Nelson Videla , Grigoris Panotopoulos

We analyze multi-field inflationary systems which yield strongly scale dependent non-Gaussianity with a shape that is very close to the local shape. As in usual multi-field models, the non-Gaussianity arises from the non-linear transfer of…

Cosmology and Nongalactic Astrophysics · Physics 2010-05-27 Jason Kumar , Louis Leblond , Arvind Rajaraman

We compute the three-point correlation function of primordial scalar density perturbations in a general single-field inflationary scenario, where a scalar field phi has a direct coupling with the Ricci scalar R and the Gauss-Bonnet term GB.…

Cosmology and Nongalactic Astrophysics · Physics 2011-04-22 Antonio De Felice , Shinji Tsujikawa

The dominant contribution to the primordial curvature perturbation may be generated at the end of inflation. Taking the end of inflation to be sudden, formulas are presented for the spectrum, spectral tilt and non-gaussianity. They are…

Astrophysics · Physics 2009-11-13 David H. Lyth

We perform a general study of primordial scalar non-Gaussianities in single field inflationary models in Einstein gravity. We consider models where the inflaton Lagrangian is an arbitrary function of the scalar field and its first…

High Energy Physics - Theory · Physics 2009-11-11 Xingang Chen , Min-xin Huang , Shamit Kachru , Gary Shiu

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

In this paper I review the theory and numerical simulations of non-linear dynamics of preheating, a stage of dynamical instability at the end of inflation during which homogeneous inflaton explosively decays and deposits its energy into…

General Relativity and Quantum Cosmology · Physics 2015-03-14 Andrei V. Frolov
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