The proposed research will focus on the investigation of non-supersymmetric string theories and time dependent dynamics in string theory. It explores the relation of nonsupersymmetric string theories to supersymmetric string theories as well as M-Theory. The focus will be on using tachyon condensation to relate these theories. The methods that will be used are conformal field theory and renormalization group Another focus of the research is the resolution of space-time singularities in string theories that are defined on spaces that are geometrically singular such as orbifolds and conifolds. To understand cosmological and other space-like singularities new tools will need to be developed. We propose to study time dependent dynamics in string theory in order to understand whether there are viable alternatives to the inflationary paradigm of cosmology.
