Related papers: Non-Gaussianity from Attractor Curvaton
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…
We analyse the primordial density perturbation when it is generated by a `curvaton' field different from the inflaton. In some cases this perturbation may have large isocurvature components, fully correlated or anti-correlated with the…
In this article, we show that a stochastic form of scale-dependent halo bias arises in multi-source inflationary models, where multiple fields determine the initial curvature perturbation. We derive this effect for general non-Gaussian…
Recently we studied inflation models in which the inflaton potential is characterized by an underlying approximate global symmetry. In the first work we pointed out that in such a model curvature perturbations are generated after the end of…
In contrast to the inflaton's case, the curvature perturbations due to the curvaton field depend strongly on the evolution of the curvaton before its decay. We study in detail the dynamics of the curvaton evolution during and after…
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…
A recent variant of the inflationary paradigm is that the ``primordial'' curvature perturbations come from quantum fluctuations of a scalar field, subdominant and effectively massless during inflation, called the ``curvaton'', instead of…
We suppose that a vector field perturbation causes part of the primordial curvature perturbation. The non-Gaussianity parameter fNL is then, in general, statistically anisotropic. We calculate its form and magnitude in the curvaton scenario…
In this study, we explore the back reaction of phase transitions in the spectator sector on the inflaton field during slow-roll inflation. Due to the significant excursion of the inflaton field, these phase transitions are likely to occur…
Cosmological inflation generates a spectrum of density perturbations that can seed the cosmic structures we observe today. These perturbations are usually computed as the result of the gravitationally-induced spontaneous creation of…
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…
We point out a possible generation mechanism of non-Gaussian bubbles in the sky due to bubble nucleation in the early universe. We consider a curvaton scenario for inflation and assume that the curvaton field phi, whose energy density is…
We analyze primordial non-gaussianities in presence of an ultra-slow phase during the inflationary dynamics, focusing on scenarios relevant for the production of primordial black holes. We compute the three-point correlation function of…
We study inflation in the $\alpha-$attractor model under a non-slow-roll dynamics with an ansatz proposed by Gong \& Sasaki \cite{Gong:2015ypa} of assuming $N=N\left(\phi\right)$. Under this approach, we construct a class of local shapes of…
Primordial non-Gaussianity signatures of extremely heavy particles are re-examined within a simple alternative to the standard inflationary paradigm, in which the primordial fluctuations and the inflationary spacetime expansion are sourced…
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…
This article investigates the generation of non-Gaussianity during inflation. In the context of multi-field inflation, we detail a mechanism that can create significant primordial non-Gaussianities in the adiabatic mode while preserving the…
In the curvaton scenario, the curvature perturbation is generated after inflation at the curvaton decay, which may have a prominent non-Gaussian effect. For a model with a non-trivial kinetic term, an enhanced curvature perturbation on a…
We investigate the isocurvaton model, in which the isocurvature perturbation plays a role in suppressing the curvature perturbation, and large non-Gaussianity and gravitational waves can be produced with no isocurvature perturbation for…
We study the stability of an inflaton condensate in the presence of attractive inflaton self-interactions, in order to determine analytical conditions on the self-interaction couplings under which the condensate undergoes fragmentation. As…