The proposed research focuses on three central topics related to the inflationary universe. First, the PI will focus on the large scale structure of the eternally inflating universe and consider models where the dark energy is a stochastic parameter which varies from one place to another. The observational consequences of such models will be investigated and compared to data. Secondly the PI will continue a systematic investigation of the formation, evolution and observational signatures of various topological defects including those postulated in "braneworld" scenarios. Thirdly the PI will investigate the consequences of the new cosmological paradigm connected with eternal inflation and publish a popular book on the subject.