Topics in String Theory and Quantum Field Theory

This award funds the research activities of Professor Jeffrey A. Harvey at the University of Chicago. There are four known forces in nature: the force of gravity, the electromagnetic force, and the weak and strong forces which play a role in nuclear physics. The framework of quantum field theory gives us a mathematical description of all the forces except for gravity, and string theory is a promising, but experimentally untested, framework for unifying gravity with the other forces of nature. Quantum field theories and string theories are not fully understood. One way to unravel their structure is to focus on certain parts of these theories which constrain their structure. This project will uncover new approaches to these theories by studying the algebraic structure of special states known as "BPS states" and will also study the precise nature of the symmetries of these theories. This research advances the national interest by increasing our understanding of nature at its most fundamental level --- an understanding that in the past has eventually led to concrete applications in improved technology and medicine. The broader impacts of this research include training for postdocs who will become future scientific leaders and will involve presentations of their research in seminars and public lectures. At a more technical level, Professor Harvey will study the algebra of BPS states in both quantum field theory and string theory and its consequences for weak-strong coupling duality. He will also assess whether symmetries in string theory are always gauge symmetries, and if this turns out to be correct, will study how one can construct the co-dimension-two defects in string theory which are implied by the existence of gauge symmetries. Other aspects of his research will include a search for exceptional or sporadic rational conformal field theories. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.