Related papers: Curvaton Dynamics and the Non-Linearity Parameters…
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…
We study the axion-type curvaton model, with emphasis on the large field regime where analytic results are very difficult to obtain. We evaluate the tensor-scalar ratio $r$ using WMAP normalization and the non-linearity parameters $f_{NL}$…
We demonstrate novel features in the behavior of the second and third order non-linearity parameters of the curvature perturbation, namely, $f_{NL}$ and $g_{NL}$, arising from non-linear motion of curvaton field. We investigate two classes…
The evolution of the curvature perturbation is highly non-trivial for curvaton models with self-interactions and is very sensitive to the parameter values. The final perturbation depends also on the curvaton decay rate $\Gamma$. As a…
We investigate non-Gaussianities in self-interacting curvaton models treating both renormalizable and non-renormalizable polynomial interactions. We scan the parameter space systematically and compute numerically the non-linearity…
We show that the local type non-Gaussianity in a class of curvaton models is suppressed, i.e. the non-linearity parameters f_{NL} and those related with higher order statistics can be at most O(1), even if the curvaton energy density is…
We characterise the primordial perturbations produced due to both inflaton and curvaton fluctuations in models where the curvaton has a quadratic, cosine or hyperbolic potential, and the inflaton potential is characterised by the usual…
We investigate density perturbations sourced by a curvaton with a generic energy potential. The key feature of a curvaton potential which deviates from a quadratic is that the curvaton experiences a non-uniform onset of its oscillation.…
We revise the Non-Gaussianity of canonical curvaton scenario with a generalized $\delta N$ formalism, in which it could handle the generic potentials. In various curvaton models, the energy density is dominant in different period including…
We consider curvaton models with potentials that depart slightly from the quadratic form. We show that although such a small departure does not modify significantly the Gaussian part of the curvature perturbation, it can have a pronounced…
We study the curvaton scenario using gauge-invariant second order perturbation theory and solving the governing equations numerically. Focusing on large scales we calculate the non-linearity parameter f_nl in the two-fluid curvaton model…
We investigate how the background evolution affects the curvature perturbations generated by the curvaton, assuming a curvaton potential that may deviate slightly from the quadratic one, and parameterizing the background fluid density as…
In this paper, we will use $\delta \mathcal{N}$-formalism to calculate the primordial curvature perturbation for the curvaton model with a Lagrange multiplier field. We calculate the non-linearity parameters $f_{NL}$ and $g_{NL}$ in the…
In general a weakly self-interacting curvaton field is expected and the curvaton potential takes the polynomial form. The curvaton potential can be dominated by the self-interaction term during the period of inflation if the curvaton field…
We show how to build a curvaton inflationary model motivated by scale-dependent non-Gaussianities of cosmological perturbations. In particular, we study the change of sign in the $f_{NL}$ parameter as a function of the curvaton field value…
We discuss observational consequences of the curvaton scenario, which naturally appears in the context of the simplest model of chaotic inflation in supergravity. The non-gaussianity parameter f_NL in this scenario can take values in the…
We discuss non-Gaussianity and baryonic isocurvature fluctuations in the curvaton scenario, assuming that the baryon asymmetry of the universe originates only from the decay products of the inflaton. When large non-Gaussianity is realized…
We study non-Gaussianity of density perturbations generated by an axionic curvaton, focusing on the case that the curvaton sits near the hilltop of the potential during inflation. Such hilltop curvatons can generate a red-tilted density…
The generation of non-gaussianity is studied in a three fluid curvaton model. By utilizing second order perturbation theory we derive general formulae for the large scale temperature fluctuation and non-gaussianity parameter, $f_{NL}$, that…
We present a systematic study of the amplitude of the primordial perturbation in curvaton models with self-interactions, treating both renormalizable and non-renormalizable interactions. In particular, we consider the possibility that the…