Cosmological scaling solutions (and their applications to string scenarios)

Abstract

Cosmology has undergone a significant advance in recent years both observationally and theoretically. New high quality data from a host of Cosmic Microwave Background and high redshift surveys has provided strong support for the inflationary paradigm, which postulates that the universe expanded exponentially fast when it was a fraction of a second old. A key question that has arisen is the nature of the underlying physics that drove such a phase of accelerated expansion. An exciting theoretical development has been the realization that the standard model interactions may be confined to a four–dimensional brane, whereas gravitational interactions may also propagate through the extra dimensions. The radical proposal of the ‘braneworld scenario’ is that our observable universe is a brane embedded in a higher–dimensional bulk. We will review some of the recent developments in this field.