We present a phase-plane analysis of cosmologies containing a barotropic fluid with equation of state pγ = (γ − 1)ργ, plus a scalar field φ with an exponential potential V ∝ exp(−λκφ) where κ = 8πG.… (More)

We investigate the end of the inflationary period in the recently proposed scenario of locked inflation, and consider various constraints arising from density perturbations, loop corrections,… (More)

Aspects of superstring cosmology are reviewed with an emphasis on the cosmological implications of duality symmetries in the theory. The string effective actions are summarized and toroidal… (More)

We consider the construction of inverted hybrid inflation models in which the vacuum energy during inflation is at the TeV scale, and the inflaton couples to the Higgs field. Such models are of… (More)

Scalar field theory has become the generic playground building cosmological models related to particle physics, particular for obtaining inflationary cosmologies. One su class of models involves… (More)

Measurements of the redshift-luminosity distance relat using high redshift type Ia supernovas combined with cos microwave background~CMB! and galaxy clusters data ap pear to suggest that the present… (More)

We propose a scenario for inflation based upon the braneworld picture, in which high-energy corrections to the Friedmann equation permit inflation to take place with potentials ordinarily too steep… (More)

In many inflationary models, a large amount of energy is transferred rapidly to the long-wavelength matter fields during a period of preheating after inflation. We study how this changes the dynamics… (More)

Pre–big bang models of inflation based on string cosmology produce a stochastic gravitational wave background whose spectrum grows with decreasing wavelength, and which may be detectable using… (More)

Quintessence has been introduced as an alternative to the cosmological constant scenario to account for the current acceleration of the universe. This new dark energy component allows values of the… (More)