相关论文: Mode - mode coupling and primordial fluctuations
Recent observations suggest that the spectral index of the primordial perturbations is very close to unity, as expected in models of slow roll inflation. It is still possible for such models to produce spectra which are scale dependent. We…
The scalar mode density perturbations in a the warm inflationary scenario are analysed with a view to predicting the amount of non-gaussianity produced by this scenario. The analysis assumes that the inflaton evolution is strongly damped by…
Until recently our knowledge of the primordial curvature perturbation was relatively modest. Ever since COBE delivered its map of data we know the scalar spectrum of primordial perturbations is approximately flat, with the power being only…
We study the linear perturbation of the recently proposed model of inflation where a uniform gauge-kinetic coupling of the inflaton to multiple vector fields breaks the cosmic no-hair conjecture while maintaining the isotropy. We derive the…
Slow-roll inflation is a successful paradigm. However we find that even a small coupling of the inflaton to other light fields can dramatically alter the dynamics and predictions of inflation. As an example, the inflaton can generically…
Usual inflation is realized with a slow rolling scalar field minimally coupled to gravity. In contrast, we consider dynamics of a scalar with a flat effective potential, conformally coupled to gravity. Surprisingly, it contains an attractor…
The inflaton field responsible for inflation may not be a canonical fundamental scalar. It is possible that the inflaton is a composite of fermions or it may have a decay width. In these cases the standard procedure for calculating the…
In some versions of the theory of inflation, it is assumed that before inflation began the universe was in a Friedmann-Robertson-Walker (FRW) stage, with the energy density dominated by massless particles. The origin of the nearly…
We study the production of primordial circular ("V-mode") polarization in axion inflation coupled to fermions and gauge fields, with special attention paid to (p)reheating. We construct the power spectrum of $V$, and find a blue-tilted…
We study the effects of primordial magnetic fields on the inflationary potential in the context of a warm inflation scenario. The model, based on global supersymmetry with a new-inflation-type potential and a coupling between the inflaton…
We investigate the coupling between the inflaton and massive vector fields. All renormalizable couplings with shift symmetry of the inflaton are considered. The massive vector can be decomposed into a scalar mode and a divergence-free…
There exist several models of inflation that produce primordial bispectra that contain a large number of oscillations. In this paper we discuss these models, and aim at finding a method of detecting such bispectra in the data. We explain…
We discuss the possibility of generating adiabatic density perturbations from spatial fluctuations in the inflaton decay rate which are due to quantum fluctuations of light moduli fields coupling to the inflaton. We point out that…
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 analyze the impact of breaking diffeomorphism invariance in the inflaton sector. In particular, we consider inflaton models which are invariant under the subgroup of transverse diffeomorphisms and address the possibility of implementing…
Inflation models are compared with observation on the assumption that the curvature perturbation is generated from the vacuum fluctuation of the inflaton field. The focus is on single-field models with canonical kinetic terms, classified as…
Using the O(N) model as an example, we investigate the self-interaction effects of inflaton on the dynamics of the primordial perturbations. When taking interactions into account, it is essential to employ a self-consistent off-equilibrium…
The primordial spectra are calculated using dispersion relations which deviate from the relativistic one above a certain energy scale Lambda. We determine the properties of the leading modifications with respect to the standard spectra when…
The possibility of thermally induced initial density perturbations in inflationary cosmology is examined. The fluctuation dynamics of a scalar field plus thermal bath system during slow roll is described by a Langevin-like equation.…
We investigate if the observed small and nearly scale-invariant primordial cosmic perturbation, i.e. the perturbation amplitude $P_\zeta\sim10^{-9}$ and the spectral index $n_s \simeq 0.965$, is typical in the landscape of vacua after…