It is shown that density perturbations in hybrid inflation models of the new type can be very large on the scale corresponding to the phase transition, which could lead to a copious production of black holes in these models.Expand

It is shown that the usual method of solving the linearized perturbation equations is equivalent to the recently proposed analysis of Sasaki and Stewart in terms of the perturbed expansion along neighboring trajectories in field-space.Expand

It is shown here that a nonminimal conformal coupling of the inflaton to the curvature scalar, as well as radiative corrections to the effective potential, may provide a dynamical cutoff and generate stationary solutions for chaotic inflation potentials.Expand

A new mechanism is proposed which may help solve the cosmological constant problem and is given examples of models where each of these possibilities can be realized, and some implications for quantum cosmology are discussed.Expand

It is found that in some inflationary models the probability distribution P_p rapidly approaches a stationary regime, and the shape of the distribution depends, however, on the choice of the time parametrization.Expand

We show how observations of the perturbation spectra produced during inflation may be used to constrain the parameters of general scalar-tensor theories of gravity, which include both an inflaton and… Expand

The parameters of the models of open inflation are constrain so that these modes do not distort the observed temperature anisotropy of the microwave background.Expand

It is concluded that general relativity is an attractor during the quantum diffusion of the fields, which leads to runaway solutions with infinitely large values of the Planck mass after inflation.Expand

An exact expression for the amplitude of quantum fluctuations on all scales in the limit where the backreaction on the metric is neglected is given, a very good approximation for values of the inflaton field well below the Planck scale.Expand