Related papers: Correlating correlation functions of primordial pe…

In this review, we discuss how non-Gaussianity of cosmological perturbations arises from inflation. After introducing the in-in formalism to calculate the $n$-point correlation function of quantum fields, we present the computation of the…

We explore a new possibility that some inflaton fields in multi-field inflation models satisfy the observed value of the spectral index so that the curvature perturbation generated by them through post-inflationary dynamics may be relevant…

We study an inflationary scenario where thermal inflation is followed by fast-roll inflation. This is a rather generic possibility based on the effective potentials of spontaneous symmetry breaking in the context of particle physics models.…

We investigate the symmetry constraints on the bispectrum, i.e. the three-point correlation function of primordial density fluctuations, in slow-roll inflation. It follows from the defining property of slow-roll inflation that primordial…

We use the delta N-formalism to describe the leading order contributions to the primordial power spectrum, bispectrum and trispectrum in multiple-field models of inflation at leading order in a perturbative expansion. In slow-roll models…

The leading quantum correction to the power spectrum of a gravitationally-coupled light scalar field is calculated, assuming that it is generated during a phase of single-field, slow-roll inflation.

We develop a variant of the generalized slow roll approach for calculating the curvature power spectrum that is well-suited for order unity deviations in power caused by sharp features in the inflaton potential. As an example, we show that…

We study primordial perturbations from hyperinflation, proposed recently and based on a hyperbolic field-space. In the previous work, it was shown that the field-space angular momentum supported by the negative curvature modifies the…

We investigate the inhomogeneous inflation, in which the space exponentially expands with inhomogeneities, and its cosmological perturbations. The inhomogeneous inflation is realized by introducing scalar fields with spacelike gradients…

In inflationary cosmology, the form of the potential is still an open problem. In this work, second-order effects of the inflationary potential are evaluated and related to the known formula for the primordial perturbations at a wide range…

In this letter, we propose a model of inflationary cosmology with a bounce preceded and study its primordial curvature perturbations. Our model gives rise to a primordial power spectrum with a feature of oscillation on large scales compared…

We consider the generation of primordial curvature perturbation by general non-Abelian vector fields without committing to a particular group. Self-interactions of non-Abelian fields make the field perturbation non-Gaussian. We calculate…

Thermal fluctuations provide the main source of large scale density perturbations in warm inflationary models of the early universe. For the first time, general results are obtained for the power spectrum in the case when the friction…

In a variety of inflation models the motion of the inflaton may trigger the production of some non-inflaton particles during inflation, for example via parametric resonance or a phase transition. Particle production during inflation leads…

We analyse models of inflation in which isocurvature perturbations present during inflation are converted into the primordial curvature perturbation during instant preheating. This can be due to an asymmetry between the fields present…

Enormous information about interactions is contained in the non-Gaussianities of the primordial curvature perturbations, which are essential to break the degeneracy of inflationary models. We study the primordial bispectra for G-inflation…

We study a class of generalized inflation models in which the inflaton is coupled to the Ricci scalar by a general $f(\phi, R)$ term. The scalar power spectrum, the spectral index, the running of the spectral index, the tensor mode spectrum…

We calculate the bispectrum of primordial curvature perturbations, \zeta, generated during "open inflation." Inflation occurs inside a bubble nucleated via quantum tunneling from the background false vacuum state. Our universe lives inside…

We study the effects of a class of features of the inflaton potential, corresponding to discontinuties in its derivatives. We perform fully numerical calculations and derive analytical approximations for the curvature pertubations spectrum…

We derive a theoretical upper bound on the oscillation frequency in the scalar perturbation power spectrum of single-field inflation. Oscillations are most naturally produced by modified vacua with varying phase. When this phase changes…