This award funds the research activities of Professors Ira Wasserman, Eanna Flanagan, and Rachel Bean at Cornell University.
It has been more than a decade since the first hints that the expansion of the Universe is accelerating were inferred from observations of Type Ia supernovae at cosmological distances. This unexpected observation could be explained if the Universe is pervaded by dark energy, which could be in the form of a cosmological constant. Although particle theories, including string theory, can accommodate a cosmological constant, they generally require a much larger value than is compatible with the nature of the Universe revealed by cosmological observations. As a result, the ultimate cause of the acceleration of the Universe remains obscure, and other theoretical possibilities exist. The research of Wasserman, Flanagan, and Bean will examine these important issues in various different studies. One study will examine how accurately it can be established that the dark energy is indeed a cosmological constant. The PI's will also investigate phenomenological implications of higher dimensions for the expansion of the Universe.
This research will also have broader impacts, primarily via the training of Cornell Ph.D. students. The proposed research is multidisciplinary in nature, and will further develop already-existing ties between the particle physics, string theory and relativity groups at Cornell. In addition to disseminating their work via conventional academic channels (journal publications, seminars, conferences), the three investigators are deeply involved in programs aimed at communicating the latest scientific results to the general public.
