Thurston 9701755 This award provides core support to the Mathematical Sciences Research Institute located in Berkeley, California. The fundamental goal of the Mathematical Sciences Research Institute (MSRI) is to stimulate research in the mathematical sciences by bringing together, in a programmatically focused scientific environment, the top mathematical scientists, nationally and internationally, in given research subjects. The interaction of senior and mid-level scholars and the very best postdoctoral fellows in a given field produces a stimulating environment where new ideas can be exploited and developed. The training of postdoctoral researchers is a priority of MSRI, and the scientific structure and budgetary allocations of funds reflect this. Normally, two academic-year scientific research programs take place each year. In addition to these academic year programs, MSRI conducts workshops and conferences. MSRI also supports summer research and training programs for graduate students. Programs are scheduled that reflect timely research interest and opportunities for cross-programmatic collaboration and scientific exchange.