In cosmology, my work has focused on issues at the interface between fundamental physics (particle physics and string theory), general relativity and astrophysics. The mechanisms for driving inflationary expansion in the early universe, the connection between inflation and elementary particles, a...
In cosmology, my work has focused on issues at the interface between fundamental physics (particle physics and string theory), general relativity and astrophysics. The mechanisms for driving inflationary expansion in the early universe, the connection between inflation and elementary particles, and the observational consequences of inflation are subjects of longstanding interest. Over the last decade, my research has turned to an alternative known as the "cyclic universe," in which the big bang is not the beginning of space and time but rather a bounce from a pre-existing phase of contraction into a phase of expansion accompanied by the creation of hot matter and radiation; the key events that smoothed and flattened the universe occur before the last bang; dark energy plays a role in smoothing and flattening the universe prior to the next contraction phase and next big bang; and the entire cycle repeats every trillion years or so. This is a very fruitful area of research. We have recently found that there are numerous methods for smoothing and flattening the universe during a contracting phase (such as ekpyrotic and anamorphic mechanisms) and in having the universe bounce. We are developing these ideas and seeking ways of distinguishing them observationally.