In these lectures I review recent attempts to apply string theory to
cosmology, including string cosmology and various models of brane cosmology. In
addition, the review includes an introduction to inflation as well as a
discussion of transplanckian signatures. I also provide a critical discussion
of the possible role of holography. The material is based on lectures given in
January 2004 at the RTN String School in Barcelona, but also contain some
additional material.Comment: Lectures given in January 2004 at the RTN Barcelona String School, 50
pages, 9 figure