The importance of the field of Condensed Matter Physics can hardly be overstated. It deals with matter at everyday energies and with length and times scales in which complex processes are able to occur. It is a field in which much experimental and th...
The importance of the field of Condensed Matter Physics can hardly be overstated. It deals with matter at everyday energies and with length and times scales in which complex processes are able to occur. It is a field in which much experimental and theoretical effort has been invested. New experimental techniques continue to shift the boundaries of this diverse field. Yet the theoretical tools that have been brought to bear on these problems have had a distinctly stale flavor. Only recently have theorists woken up to the possibility that modern techniques developed mainly by particle theorists could be fruitfully applied to study these problems. The aim of this thesis is therefore to study important physical phenomena in Condensed Matter Physics using tools that are powerful enough to be able to probe new physics. In the first part of this thesis I have shown how transient Many-Body phenomena may be studied using nonequilibrium Green functions. In the second half I have developed a new nonpertubative tool called bosonization and applied it to study the all-important question at the frontier of Condensed Matter Theory namely when does Fermi liquid theory break down and when it does what new physical principles need to be invoked in order to understand physical phenomena in this new and uncharted regime.