We analyze diffeomorphism invariance in inflationary spacetimes regulated by a boundary at late time. We present the action for quadratic fluctuations in the presence of a boundary, and verify that it is gauge invariant precisely when the correct local counterterms are included. The scaling behavior of bulk correlation functions at the boundary is determined by Callan-Symanzik equations which p...

An introductory account is given of the inflationary cosmology, which postulates a period of accelerated expansion during the Universe’s earliest stages. The historical motivation is briefly outlined, and the modelling of the inflationary epoch explained. The most important aspect of inflation is that it provides a possible model for the origin of structure in the Universe, and key results are ...

The inflationary attractor properties of the canonical scalar field and Born-Infeld field are investigated in the Randall-Sundrum II scenario with a Gauss-Bonnet term in the bulk action. We find that the inflationary attractor property will always hold for both the canonical and Born-Infeld fields for any allowed non-negative Gauss-Bonnet coupling. We also briefly discuss the possibility of exp...

I review the general aspects of cosmological parameter estimation from observations of the cosmic microwave background (CMB) temperature anisotropies in the framework of inflationary adiabatic models. The most recent CMB datasets are starting to give good constraints on the relevant parameters of inflationary adiabatic models. They point toward a model consistent with the basic predictions of i...

We present a supergravity inflationary scenario in which the inflaton field takes values considerably larger than the Planck scale. It is based on a class of inflationary potentials which can be derived from “singular” Kähler potentials assuming simple superpotentials of the type W ∼ S. To this class belong, among many others, all potentials which are even infinitesimally smaller than the one d...

In this work we study the particle production in time dependent periodic potential using the method of complex time WKB (CWKB) approximation. In the inflationary cosmology at the end of inflationary stage, the potential becomes time dependent as well as periodic. Reheating occurs due to particle production by the oscillating inflaton field. Using CWKB we obtain almost identical results on catas...

We investigate the possibility for a direct detection by future space interferometers of the stochastic gravitational wave (GW) background generated during the inflationary stage in a class of viable ΛCDM BSI models. At frequencies around 10Hz, maximal values Ωgw(ν) ∼ 3 × 10 are found, an improvement of about one order of magnitude compared to single-field, slowroll inflationary models. This is...

I n setting monetary policy in 1995, the Federal Reserve sought to promote sustainable economic growth and continued progress toward price stability. Toward those ends, the Federal Reserve adjusted the stance of monetary policy three times in 1995. In February, amid signs of increasing inflationary pressures, policy was tightened. In July and December, in response to signals of a slowing econom...

We present a new approximation scheme that allows us to increase the accuracy of analytical predictions of the power spectra of inflationary perturbations for two specific classes of inflationary models. Among these models are chaotic inflation with a monomial potential, power-law inflation and natural inflation (inflation at a maximum). After reviewing the established first order results we ca...

According to the standard lore, a prolonged inflation leaves quantum field theory in cold, low entropy state. Thus, some mechanism is needed reheat this post-inflationary state, leaving hot, thermal, radiation-dominated Universe. Typically, reheating achieved coupling inflaton QFT degrees of freedom. We argue that nonequilibrium dynamics non-conformal (post-)inflationary background space-time c...