In previous work, we showed that the answer to the question posed in the title cannot be found within an equilibrium setting. The inclusion of dynamical backreaction effects from massive long wavelength modes on the initial DeSitter patches results in gravitational instabilities that cleanse the phase space of inflationary initial conditions of all regions except those allowing high energy infl...

Single-field inflationary models predict nearly Gaussian initial conditions, and hence a detection of non-Gaussianity would be a signature of the more complex inflationary scenarios. In this paper we study the effect on the cosmic microwave background and on large-scale structure from primordial nonGaussianity in a two-field inflationary model in which both the inflaton and curvaton contribute ...

We consider constraints on inflation driven by a single, minimally coupled scalar field in the light of the WMAP5 dataset, as well as ACBAR and the SuperNova Legacy Survey. We use the Slow Roll Reconstruction algorithm to derive optimal constraints on the inflationary parameter space. The scale dependence in the slope of the scalar spectrum permitted by WMAP5 is large enough to lead to viable m...

We consider the effects on the primordial power spectrum of a period of radiation-dominated expansion prior to the inflationary era. If inflation lasts a total of only 60 e-folds or so, the boundary condition for quantum modes cannot be taken in the short-wavelength limit as in the standard perturbation calculation. Instead, the boundary condition is set by the vacuum state of the prior radiati...

This paper undertakes an exploratory analysis of the inflationary dynamics within the Croatian economy over the period January 1992 December 1999. Recognizing the structural break in the inflationary process corresponding to the anti-inflationary stabilization program of October 1993, the analysis proceeds by estimating an augmented vector autoregressive (VAR) model of the log first-differences...

We present inflationary models of the early universe in the braneworld scenario considering both scalar field and tachyon field separately. The technique of Chervon and Zhuravlev to obtain inflationary cosmological models without restrictions on a scalar field potential is employed here. We note that like scalar field, the inflationary solution obtained here with tachyon field also does not dep...

Even simple inflationary scenarios have many free parameters. Beyond the variables appearing in the inflationary action, these include dynamical initial conditions, the number of fields, and couplings to other sectors. These quantities are often ignored but cosmological observables can depend on the unknown parameters. We use Bayesian networks to account for a large set of inflationary paramete...

Inflationary attractors predict the spectral index and tensor-to-scalar ratio to take specific values that are consistent with Planck. An example is the universal attractor for models with a generalised non-minimal coupling, leading to Starobinsky inflation. In this letter we demonstrate that it also predicts a specific relation between the amplitude of the power spectrum and the number of e-fo...

Estimates of inflationary parameters from the CMB B-mode polarization spectrum on the largest scales depend on knowledge of the reionization history, especially at low tensor-to-scalar ratio. Assuming an incorrect reionization history in the analysis of such polarization data can strongly bias the inflationary parameters. One consequence is that the single-field slow-roll consistency relation b...

We present a class of exact solutions to the constraint equations of General Relativity coupled to a Klein Gordon field, these solutions being isotropic but not homogeneous. We analyze the subsequent evolution of the consistent Cauchy data represented by those solutions, showing that only certain special initial conditions eventually lead to successfull Inflationary cosmologies. We argue, howev...