Early Universe Cosmology has matured from a purely speculative theoretical endeavour into an experimentally testable field. In 1992 the COBE satellite detected small temperature anisotropies in the Cosmic Microwave Background radiation to one part in 10^5. These anisotropies are predicted to arise from small quantum fluctuations produced during the first 10^-35 seconds after the Big Bang.
The standard Big Bang scenario although very successful to explain cosmological observations, has some important shortcomings. Particle Physics in connection with Cosmology provide natural candidates to solve these problems, and the inflationary scenario seems to be a verifiable candidate. Inflation is based on Particle Physics models that provide for a period of accelerated expansion of the Universe, explaining why the energy density is so close to critical and the homogeneity of the Cosmic Microwave Backgroung. At the same time the small quantum fluctuations of the fields of the Particle Physics models provide the seeds for the anisotropies of the CMB and for the formation of large scale structure such as galaxies and superclusters through the growth of these fluctuations via gravitational instability.
Our program seeks to provide a consistent formulation of the inflationary scenario by implementing new methods of Quantum Field Theory to understand the microscopic evolution of the Particle Physics models. The ultimate goal is to provide reliable results for the power spectrum of density perturbations and gravitational waves to compare to the experimental data.
The field is being revolutionized by current and future experiments
that seek to detect temperature anisotropies at smaller angular scales
and promises to be one of the most fascinating arenas for discoveries into
the next century.