The members of the group are primarily interested in quantum field theories and string theories, and especially in the interplay between mathematics and physics in these theories. Quantum field theory is a framework that combines quantum mechanics and special relativity in a self-consistent manner, and underpins most of theoretical physics today. Over the past 40 years, string theory has emerged as the leading candidate for a unifying theory of the fundamental forces of nature. It assumes that all particles are different harmonics of small vibrating strings, much in the way the different harmonics of a guitar string correspond to different musical notes. What is perhaps less well-known is the rich and fruitful interplay between quantum field theory, string theory and mathematics. New and sophisticated mathematical techniques have rendered many problems in string theory and quantum field theory tractable and in certain cases exactly soluble. Conversely, string theory has also led to striking advances and conjectures in mathematics. It is this bridge between theoretical physics and mathematics that forms the foundation of our research.